这项工作得到了国家科学基金会的支持 [材料和结构的力学方案, 赠款编号 1562656];和美国机械工程师学会 [Haythornthwaite 青年研究员奖]。

1. 程序集和对齐 <ol> <li> 选择一个悬臂, 其刚度适合于预期的实验。使用 #4-40 插槽头帽螺钉 (SHCSs) 将 LP 连接到悬臂上 (请参见 图 3 A )。在连接 LP 时, 注意不要塑性变形变形悬臂. </li>
</ol> <img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/56571/56571fig3.jpg"/> 图 3: 装配悬臂式力传感器的程序和测量它的刚度. ( A ) 将负载点 (LP) 连接到悬臂 (C) 上, 并将负载点尖 (LPT) 向上指向。( B ) 悬臂和 LP 组件连接到悬臂板上, 表示为 CP。悬臂板的凹口袋显示在悬臂式臂下面。( C ) 将悬臂板连接到框架的下侧, 以便显示在 ( B ) 中的板的侧面朝向 <img alt="Equation 6" src="/files/ftp_upload/56571/56571eq6.jpg"/> 方向。FODS 千分尺表示为 FM. ( D ) 在该协议的 步骤 2 中使用的线钩和校准权重显示在 LPT 的孔中。<a href="//ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56571/56571fig3large.jpg" target="_blank"> 请单击此处查看此图的较大版本. </a> 
<ol start="2"> <li> 将几滴 2-丙醇应用于皮棉免费棉签, 并擦拭 LP 镜的表面。检查镜像是否有划痕, 并在损坏时更换镜像. </li>
	<li> 松散地将悬臂梁连接到悬臂板上, 使用 #6-32 SHCSs, 该板的侧面包含凹槽口袋, 其上的 LPT 指向远离板 (请参见 图 3 B )。插入1/8 和 #34; 对齐针脚通过悬臂和板, 拧紧螺钉, 然后卸下对齐针脚. </li>
	<li> 通过逆时针旋转 FODS 微米 (请参见 图 3 C ), 尽可能地收回 FODS。松散地将悬臂板连接到框架上, 使用 #6-32 SHCSs, 将 LPT 指向 <img alt="Equation 4" src="/files/ftp_upload/56571/56571eq4.jpg"/> 方向 (请参见 图 1 A )。插入1/8 和 #34; 对齐针脚通过框架和悬臂板, 拧紧螺钉, 然后卸下对齐针脚 (请参见 图 3 C ). </li>
	<li> 打开电源, 并使用调节旋钮将电压设置为12.00 伏的恒定电压模式。然后打开电压输出, 确认在电源上显示的电流和 #39 的液晶屏是大约60-70 毫安。等待至少一个小时的电流绘制达到稳定状态, 以减少电压测量不确定度. </li>
	<li> 打开并运行 Basic_Data 程序 (请参见补充代码文件)。顺时针旋转 FODS 千分尺 (参见 图 3 C 和 图 4 A), 将 FODS 向 LP 镜像移动, 直到用户界面图上显示的输出电压达到最大值. 
	<ol> <li> 通过将 FODS 壳体一侧的设置螺钉旋转, 使电压输出为 5.0 v, 以逆时针方向旋转 FODS 千分尺以收回 FODS, 从而调整 FODS 的增益. </li>
	</ol> </li> <li> 打开显微镜照明器并调整显微镜位置, 然后使用两个手动翻译阶段进行对焦, 以使 LPT 在视图中居中。通过单击 "#39; 停止和 #39" 按钮, 停止 Basic_Data 程序. </li>
	<li> 打开马达控制器用户界面软件。使用 <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"/> 轴马达控制器上的电位器滑块将舞台移动到最大允许行程 中, img alt = "公式 6" src = "/文件/ftp_上传/56571/56571eq6. jpg "/>> 方向, 并通过单击 #39; 主页和 #39; 用户界面中的按钮设置主页位置. 
	<ol> <li> 使用 <img alt="Equation 7" src="/files/ftp_upload/56571/56571eq7.jpg"/> 轴马达控制器上的电位器滑块将舞台移动到最大允许的行程中。<img alt="Equation 8" src="/files/ftp_upload/56571/56571eq8.jpg"/> 方向并设置主位置。关闭用户界面软件. </li>
	</ol> </li> <li> 将舞台置于舞台底板上 (参见 图 4 A), 以便在平整板上的千分尺头的尖端在舞台底板草皮。将气泡级别放在隔离表上, 并调整每个表和 #39 中的压力, 将阀臂拇指螺钉旋转, 使其表面处于水平. 
	<ol> <li> 将气泡级别移动到舞台平整板的顶部, 并调整千分尺, 使其也处于水平。注意千分尺位置, 从舞台底板上取下舞台。注意: 可以在此暂停协议. </li>
	</ol> </li> </ol> <img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/56571/56571fig4.jpg"/> 图 4: 在步骤1.9 中组装的机械测试设备和协议的 3.7. ( A ) 样品阶段 (SS), 连接到翻译阶段 (TS), 并使用在舞台基板 (收缩) 上的舞台平整板 (SLP) 上的千分尺调配。舞台底板连接到隔离表的光学板。悬臂式 (C);悬臂板 (CP);光纤位移传感器 (FODS) 构成了力传感系统。( B ) 加载点 (LP) 连接到悬臂, 并且负载点尖端 (LPT) 位于采样阶段的骨针上。在弯曲试验中, 利用 FODS 测量了 LP 的位移。FODS 和 LP 镜像之间的初始距离由 ( A ) 中显示的 FODS 微米 (FM) 控制。( C ) 在采样阶段的沟槽中放置的骨针的显微图像, 位于 LPT 下方。缩放条形图 = 250 和 #181; m ( C )。<a href="//ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56571/56571fig4large.jpg" target="_blank"> 请单击此处查看此图的较大版本. </a> 
 2. 悬臂刚度测量 <ol> <li> 运行 Basic_Data 程序, 并按顺时针方向旋转 FODS 千分尺, 直到输出电压约为 4 v 通过单击 #39 停止程序; 停止和 #39; 按钮. </li>
	<li> 使用分析天平测量钢丝钩和校准重量的质量. </li>
	<li> 打开 Cantilever_Calibration 程序 (请参阅 辅助代码文件 ) 并输入所需的文件名。在用户界面的文本框中 bration 输出文件. </li>
	<li> 运行 Cantilever_Calibration 程序, 然后单击并 #39; 确定 #39; 当提示输入第一个校准权重的质量时。等待用户界面图中显示的输出电压停止振荡, 然后单击绿色和 #39; 电压稳定和 #39; 按钮以进行电压测量. </li>
	<li> 使用镊子将线钩从 LPT 上的孔中挂起, 以便钩从显微镜目标中脱离 (请参见 图 3 D)。使用镊子, 以阻尼振动的悬臂造成的附加钩. 
	<ol> <li> 在对话框中输入以克为量的钩子的质量, 然后单击并 #39; 好的 #39。与前一步一样, 等待输出电压停止振荡, 然后再单击 #39; 电压稳定和 #39; 按钮. </li>
	</ol> </li> <li> 使用镊子将第一个重量挂在钢丝钩上, 并重复上一步骤中所述的电压测量过程。重复此步骤, 直到所有校准权重都已挂起或输出电压小于 1.8 v。此时, 单击并 #39; 取消和 #39; 在该对话框中, 退出 Cantilever_Calibration 程序. </li>
	<li> 逆时针旋转 FODS 千分尺以收回 FODS。小心地从 LPT 上取下钩子和重物. 
	注意: 力校准输出文件是一个制表符分隔列表的力量应用的校准质量, 平均 100 FODS 输出电压读数和标准偏差的读数。 代表性结果 部分描述如何处理此数据文件以测量悬臂刚度. </li>
</ol> 3。标本准备 <ol> <li> 在处理 蚯蚓 海绵骨架时戴上腈手套, 并在未处理时将骨架保存在密封的容器中. 
	注意: 由于针主要由二氧化硅组成, 破碎的骨针碎片是尖锐的, 可以成为嵌入皮肤, 导致刺激. </li>
	<li> 使用一对镊子抓住一个锚骨针的远端, 并拉动从骨架中删除它 (请参见 图 2 a )。将骨针放在干净的显微镜幻灯片上. </li>
	<li> 使用 #00000 红色紫貂画笔将骨针与靠近中点的幻灯片保持距离。将一条和 #8776; 4 毫米的骨针通过推刀片对骨针两侧的画笔垂直于幻灯片表面 (参见 图 2 B )。丢弃大的远端和近端骨针段并保持 #8776; 4 mm 部分. </li>
	<li> 在10x 放大倍数下使用偏振光显微镜检查 4 mm 骨针截面 (请参见 图 2 C - E )。丢弃骨针节并返回到 步骤 3.2 (如果它缺少大量的二氧化硅层区域 (请参见 图 2 E )。处理检查骨针部分独家使用 #00000 红色紫貂刷, 以避免引入任何新的损害他们的二氧化硅层. </li>
	<li> 用刷子或压缩空气从样品阶段表面清除任何骨针碎片或其他微粒。然后, 将几滴2丙醇涂抹到皮棉免费棉签上, 然后擦拭样品阶段。避免接触舞台上涂有反射漆的部位。注: 该涂料用于减少弯曲试验中所拍摄图像中镜面反射的数量. </li>
	<li> 将骨针部分转移到示例阶段。将骨针剖面放置在沟槽上, 并在弯曲试验中使用所需的跨度, 并将其轻轻地推入 <img alt="Equation 10" src="/files/ftp_upload/56571/56571eq10.jpg"/> 指向沟槽脊的方向。确保骨针垂直于沟槽边缘 (请参见 图 2 C ). </li>
	<li> 将舞台底座放在舞台底板上, 使千分尺的尖端在舞台底板草皮。如果需要, 将舞台平整度板上的千分尺调整为协议 步骤 1.9 中所述的值. </li>
</ol> 4。电压位移插值文件 <ol> <li> 打开 Bending_Test 程序 (请参阅补充代码文件)。设置 #39; 步骤大小和 #39; 2 和 #181; #39; 最大位移和 #39; 到0.5 毫米, #39; 低压停止和 #39; 到1.5 伏; #39; 使用用户界面中显示的文本框, 使高电压停止和 #39; 到 4.6 v. 
	<ol> <li> 使用用户界面中的文本框选择所需的图像和数据目录以及输出文件名。设置和 #39; 保存图像和 #39; 在用户界面中切换到向下位置, 然后单击单词和 #39 下方的绿色矩形按钮; 电压差和 #39; 使它变得发亮. </li>
	</ol> </li> <li> 运行 Bending_Test 程序, 并等待马达控制器和照相机接口初始化. </li>
	<li> 打开照明灯并调整亮度以使 LPT 可见。顺时针旋转 FODS 千分尺, 直到用户界面图中显示的输出电压为 ~ 1.7 v. 
	<ol> <li> 使用 <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"/> 轴马达控制器上的电位器滑块在 <img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg"/> 方向上移动舞台, 直到它是〜1厘米以下的 LPT 和设置 <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"/> 轴家庭的位置, 通过单击 #34; 主页和 #34; 按钮. </li>
	</ol> </li> <li> 使用 <img alt="Equation 7" src="/files/ftp_upload/56571/56571eq7.jpg"/> 和 <img alt="Equation 11" src="/files/ftp_upload/56571/56571eq11.jpg"/> 轴马达控制器上的电位器滑块定位 LPT位于试样台上的薄钢带的中心, 在 <img alt="Equation 12" src="/files/ftp_upload/56571/56571eq12.jpg"/> 沟槽的方向上。使用 <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"/> 轴马达控制器上的电位器滑块在 <img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg"/> 方向上移动舞台, 直到舞台在显微镜和 #39 的视野中. </li>
	<li> 使用 <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"/> 轴马达控制器上的电位器滑块在 <img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg"/> 方向上移动舞台, 同时在用户界面中观察输出电压图。通过查找电压变化, 确定 LPT 与舞台和 #39 的近似位置。阶段的进一步运动。收回舞台约10和 #181; m. </li>
	<li> 单击标签和 #34 的按钮; 开始测试和 #34;。当出现提示时, 输入 0.003 V 和 0.001 mm 的值, #39; 触摸灵敏度和 #39; 和 #39; 触摸的步骤大小和 #39;, 分别。等待测试完成. 
	注意: 在这一点之后, 不要从舞台底板上取下舞台, 直到弯曲试验完成, 以确保准确的位移测量。电压位移插值输出文件是一个制表符分隔列表的平均 100 FODS 输出电压读数和标准偏差, 这些读数随着 <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"/>-每个阶段位移增量的轴阶段位置。 代表性结果 部分描述如何使用此数据文件将测量的 FODS 输出电压转换为 LP 位移. </li>
</ol> 5。弯曲测试 <ol> <li> 打开并运行 Basic_Data 程序, 并按逆时针方向旋转 FODS 千分尺, 直到用户界面图上显示的输出电压约为 3 v. 使用 "电位器" 滑块在 imgalt = "方程式 7" src = "/文件/ftp_upload/56571/56571eq7. jpg"/>> -轴马达控制器将 LPT 置于骨针上方的沟槽边缘之间 (请参见 图 4 C). 
	<ol> <li> 使用 <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"/> 轴马达控制器上的电位器滑块在 <img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg"/> 方向上移动舞台, 直到LPT 位于沟槽脊的顶部表面之下 (请参见 图 5 A )。最后, 使用 <img alt="Equation 11" src="/files/ftp_upload/56571/56571eq11.jpg"/> 轴马达控制器上的电位器滑块将沟槽脊的前表面带入焦点, 使 LP 的完整宽度介于海沟山脊通过单击 "#39; 停止和 #39" 按钮, 停止 Basic_Data 程序. </li>
	</ol> </li> <li> 打开并运行 Center_LoadPoint 程序 (请参见 补充代码文件 )。使用 <img alt="Equation 7" src="/files/ftp_upload/56571/56571eq7.jpg"/> 轴马达控制器移动舞台, 直到 LPT 几乎与右沟槽边缘接触。单击并 #34; 查找边缘和 #34; 按钮. </li>
	<li> 出现提示时, 使用 <img alt="Equation 7" src="/files/ftp_upload/56571/56571eq7.jpg"/> 轴马达控制器移动舞台, 直到该 LPT 几乎与左侧沟槽边缘接触。单击 #34; 查找边缘和 #34; 按钮。等待程序将 LPT 中途放在沟槽跨度中 (请参见 图 5 B ). 
	注意: 在这一点之后, 不调整 <img alt="Equation 7" src="/files/ftp_upload/56571/56571eq7.jpg"/> 轴马达控制器是很重要的, 因为这将导致 LPT 的失调. </li>
	<li> 打开 Bending_Test 程序。将步骤大小设置为2和 #181; m, 最大位移为 0.5 mm, 低压停止到 1.5 v, 高压停止到 4.5 v 使用用户界面中的文本框. 
	<ol> <li> 使用用户界面中的文本框选择所需的图像和数据目录以及输出文件名。设置和 #39; 保存图像和 #39; 在用户界面中切换到向上的位置, 然后单击下面的绿色矩形按钮和 #39; 电压差和 #39; 使其不亮. </li>
	</ol> </li> <li> 运行 Bending_Test 程序, 并等待马达控制器和照相机接口初始化. </li>
	<li> 使用马达控制器上的电位器滑块在 <img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg"/> 方向上移动舞台, 直到骨针在显微镜和 #39; s 的视野内。使用 <img alt="Equation 11" src="/files/ftp_upload/56571/56571eq11.jpg"/> 轴马达控制器上的电位器滑块移动舞台, 直到骨针在 LPT 下. 
	<ol> <li> 调整显微镜焦点旋钮, 使骨针在用户界面中处于焦点 (请参见 图 4 C )。逆时针旋转 FODS 千分尺, 直到输出电压约为 1.8 v. </li>
	</ol> </li> <li> 在用户界面中观看输出电压图时, 使用 z-axis 马达控制器上的电位器滑块在 <img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg"/> 方向上移动舞台。通过在舞台的进一步移动中寻找电压变化来确定 LPT 与骨针接触的近似位置。收回舞台约50和 #181; m. </li>
	<li> 单击和 #34; 开始测试和 #34; 然后等待, 直到弯曲测试完成, 并且阶段返回到 <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"/> 轴的主位置. 
	注意: 舞台将在2和 #181; m 增量 (按照协议的 步骤 5.4 中的规定) 在 <img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg"/> 方向, 弯曲骨针 (请参见 图 5 C ), 直到满足几个停止条件之一。停止的情况是: a) 到达的最大阶段位移0.5 毫米;b) 骨针中断, 程序检测到 FODS 输出电压的大落差;或 c) 达到4.5 伏的高压限值。对于停止条件 (a), 如果用户希望结束测试或覆盖以前的值, 则会出现提示。当和 #39; 重写和 #39; 选定后, 用户将有机会增加阶段置换限制或反转阶段置换步骤的方向, 以便在卸载骨针时继续收集数据。通过单击 #34、反向加载和 #34, 在测试过程中的任意点, 也可以改变舞台位移增量方向。弯曲测试输出文件与协议的 步骤 4.6 中生成的电压位移插值输出文件具有相同的结构。即, 它是一个制表符分隔列表的平均 100 FODS 输出电压读数和标准偏差, 这些读数随着 <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"/> 轴阶段位置在每个阶段位移增量。 代表性结果 部分描述了该数据文件是如何与电压位移插值文件一起使用的, 用于计算弯曲试验中的悬臂位移和阶段位移。随后, 用悬臂刚度计算了骨针上的 LPT 所施加的力. </li>
	<li> 测试完成后, 按逆时针方向旋转 FODS 千分尺, 直到 FODS 从 LPT 镜像中至少有 5 mm。然后, 小心地从舞台底板上取下舞台. </li>
</ol> <img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/56571/56571fig5.jpg"/> 图 5: 将 LPT 与沟槽和 #39 的中间对齐的过程执行弯曲测试. ( A ) 该 LPT 位于协议的 步骤 5.1 末尾的沟槽脊的顶部表面下方, 但尚未定位在中跨。( B ) 在协议的 步骤 5.2 和 5.3 中描述的居中过程之后, LPT 的位置已完成。( C ) 在弯曲测试中拍摄的骨针的显微图像。在 LPT 下方的骨针截面的位移 (<img alt="Equation 14" src="/files/ftp_upload/56571/56571eq14.jpg"/>) 被标记为示意性的。缩放条形图 = 250 和 #181; m ( A - C )。<a href="//ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56571/56571fig5large.jpg" target="_blank"> 请单击此处查看此图的较大版本. </a>

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作者没有什么可透露的。

该协议的几个步骤对于确保精确测量力和位移尤为重要。虽然这些关键步骤中的一些是通用的所有三点弯曲试验, 其他是唯一的这种机械测试装置。
在协议的步骤 1.2中, 将对 LP 镜像进行清理并检查是否有划痕, 并在协议的步骤 1.6中设置 FODS 增益。对于步骤 2、 4和协议的5 , 增益和 LP 镜像的反射率是常量非常重要的。因此, 应在弯曲测试 (步骤 5 ) 之前立即执行两个校准步骤 (协议的步骤 2和4 )。
在协议的步骤 1.9和3.7中, 该阶段相对于隔离表的表面进行调配。这些步骤确保是垂直于骨针的纵向轴的力分量. <img alt="Equation 2" src="/files/ftp_upload/56571/56571eq2.jpg">机械测试装置的框架是制造的, 使悬臂、LP 镜和 FODS 的表面都与隔离表的表面平行。这意味着, 力传感器将测量的力量和位移的组成部分正常的隔离表表面。如果舞台顶部与隔离表表面的角度对齐, 则 LPT 的测量位移将为, 其中是垂直于<img alt="Equation 53" src="/files/ftp_upload/56571/56571eq53.jpg"> <img alt="Equation 55" src="/files/ftp_upload/56571/56571eq55.jpg"> </img> <img alt="Equation 54" src="/files/ftp_upload/56571/56571eq54.jpg">骨针的纵轴 (参见图 7)。自以来, 这将导致对应用力的过度预测和对每个<img alt="Equation 56" src="/files/ftp_upload/56571/56571eq56.jpg"> </img>等式(1) 和 (2) 下的骨针位移的预测。
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/56571/56571fig7.jpg"> 
图 7: 舞台平整度对位移测量的影响(A) 舞台以一个角度倾斜,, 相对于隔离表的表面和悬臂的下表面. <img alt="Equation 53" src="/files/ftp_upload/56571/56571eq53.jpg"> </img>(B) 垂直方向上的 LP 偏移量, (参见<img alt="Equation 50" src="/files/ftp_upload/56571/56571eq50.jpg"> 图 1 (D)), 是由 FODS。垂直于骨针轴的方向上的 LP 位移分量为. <img alt="Equation 54" src="/files/ftp_upload/56571/56571eq54.jpg"> </img><a href="//ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56571/56571fig7large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
在步骤 5.1-协议的5.3中, LPT 在沟槽的跨度中处于中间位置。对中跨的 LPT 的失调将导致试样的硬度比实际的31,32更硬。也就是说, 如果在中跨中施加相同的力, 骨针的位移将比测量的要小。在中心过程完成后 (步骤 5.1-5.3 ), 可以避免将舞台从舞台底板中移除或调整x轴的舞台位置。
该方法的一个局限是, 为了减少力和位移测量的相对测量不确定度, 应选择悬臂刚度, 使 FODS 输出电压在弯曲时跨越1.8 到4.5 伏的全范围。测试.然而, 这个电压范围对应于近似地≈250µm 的悬臂位移, 与骨针位移在它失败之前大致相同 (参见图 6 (C))。这意味着悬臂和骨针有类似的刚度。虽然这是没有问题的测量弹性反应和强度性质的针, 它不排除准确测量针的韧性性能。这是因为为了确保准确测量韧性性能, 骨针中的裂纹必须以受控方式33进行传播。通常, 只有在测试设备比33更硬的情况下, 才可能出现这种情况。为了提高测试装置的刚度, 可采用更灵敏的位移传感器代替 FODS。
虽然在蚯蚓针上演示了弯曲测试协议, 但机械测试装置也可用于对其他 LBBSs 和合成材料进行三点弯曲试验。这种机械测试装置是最适合的试样, 其横截面直径范围从0.01 到1毫米和海沟跨度从1到10毫米不等。对于较大的直径, 样品阶段应重新设计, 使标本不能滚过舞台。这不是一个问题, 较小的纤维, 如针, 因为粗糙的阶段的表面是足以防止试样滚动。沟槽边缘和 LPT 的半径也应增大, 以避免在样本受支持的点31,32处引入局部损伤。此外, 舞台平整板应固定在舞台底板上 (请参见图 4A), 使用¼ "-20 插槽的头帽螺钉, 在步骤 3.7之后, 以防止当力超过≈1 N 时的舞台倾斜。
对于精确的力和位移测量, 悬臂的刚度应总是比车架的刚度小得多 (≈107 N/米)。这一要求限制了该设备可应用于≈25 N 的最大力。因此, 在进行弯曲试验之前, 必须估计试样能承受的最大力, 以确定该设备是否可用于执行测试。
这项工作提供了协议、技术图纸 (参见补充文件 1)和软件 (请参阅补充代码文件) 以复制和使用我们的机械测试设备。这将有望为精确测量许多不同 LBBSs 的弯曲行为提供一个平台。这些测量是一个先决条件, 以加深了解 LBBS 的结构和它的力学性能之间的关系。

通过研究承重生物结构 (LBBSs) (如壳体和骨骼) 的结构, 工程师们开发出了强而韧的新型复合材料 ( 1)。结果表明, LBBSs 的优异力学性能及其与生物激发的对应关系与它们错综复杂的内部结构2有关。然而, LBBS 体系结构和机械性能之间的关系还没有得到充分的了解。测量 LBBS 的机械响应是了解其结构如何增强其机械性能的第一步。
然而, 重要的是, 用于测量 LBBS 的机械响应的测试类型与它的机械性能是一致的。例如, 由于羽毛必须支持空气动力载荷, 羽毛轴的主要功能是提供弯曲刚度3。因此, 弯曲试验是首选的单轴拉伸试验, 以测量其机械响应。事实上, 许多 LBBSs-如羽毛轴3、草茎4、针5、6、7、8--主要是由弯曲引起的变形。这是因为这些 LBBSs 是细长的-即, 它们的长度比它们的宽度或深度大得多。但是, 对这些 LBBSs 执行弯曲测试是有挑战性的, 因为它们在失败之前能够承受的力和位移范围从 10 -2到 102 N 和 10-4到 10-3 m, 分别是3,4,5,7,8. 因此, 用于执行这些机械测试的设备应分别具有≈10-5 N 和≈10-7 m (即传感器最大可力和位移的 0.1%) 的力和位移分辨率。
在商业上, 大规模的机械测试系统通常无法用这个分辨率来测量力和位移。当原子力 microscope-based 9、10或机械系统11测试设备有足够的分辨率时, 它们可以测量的最大力 (各自的位移) 小于LBBS 能承受的最大力 (各自位移)。因此, 要对这些 LBBSs 进行弯曲测试, 工程师和科学家必须依靠 custom-built 机械测试设备5,7,12,13。这些 custom-built 设备的主要优点是它们可以容纳大范围的力和位移。然而, 这些设备的构造和操作在文献中没有很好的记录。
一个协议被描述为执行三点弯曲试验使用 custom-built 机械测试设备, 可以测量力量范围从 10-5到 101 N 和位移范围从 10-7到 10-2 m。辅助材料中提供了机械试验装置各部件的技术图纸, 包括所有尺寸。该机械试验装置的主要优点是可以很容易地调整力和位移范围, 以适应不同的 LBBSs。该装置的工作原理类似于原子力显微镜9。在这个装置中, 一个试样被放置在一个不锈钢板的沟槽中 (参见图 1a-c)。沟槽的跨度是从光学显微测量为1278±3µm (平均±标准偏差; n = 10)。沟槽边缘在弯曲测试期间支持试样 (请参见图 1C和D)。此采样阶段附加到一个三轴平移阶段, 并位于铝楔下, 以便楔形位于沟槽跨度的中间 (请参见图 1C)。通过在方向中移动舞台 (参见<img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg"> 图 1A和C), 将试样推入楔形, 导致试样弯曲。
我们将楔形作为负载点 (LPT) 和包含楔形的设备的组件作为负载点 (LP)。该 LP 连接到悬臂的一端, 其位移由光纤位移传感器 (FODS) 测量。FODS 发出红外光, 它反射到位于 LP 顶部表面的镜像 (请参见图 1B), 并由 FODS 中的光纤接收。用≈5 mm 方形片抛光硅片作为 lp 镜, 用环氧树脂贴在 lp 上。FODS 通过比较发射和反射光的强度来测量位移。悬臂刚度和位移是用来计算的力量,, 经验的楔由于其与标本的相互作用. <img alt="Equation 2" src="/files/ftp_upload/56571/56571eq2.jpg"> </img>悬臂位移也用于计算试样在楔形下方的截面位移,. <img alt="Equation 3" src="/files/ftp_upload/56571/56571eq3.jpg"> </img>Cantilever-based 力传感器已用于一些微型和宏观的机械测试研究10,11,12,13,14。这里介绍的具体设计是由一个用于执行粘接接触实验的机械测试装置14改编的。类似的设计也被用于商业上可用的微摩擦15,16。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56571/56571fig1.jpg"> 
图 1: custom-built 机械测试设备概述.(a) 计算机辅助设计渲染设备。舞台组件以绿色高亮显示。力传感子组件 (悬臂式、负载点 (LP)) 以红色突出显示。(B) 放大的视图 (A)。lp 镜像以蓝色显示在 FODS 下 lp 的顶部表面上, 并被标记为 "泥倾泻"。(C) 用于描述平移阶段的运动的坐标系。通过调配 the 阶段在协议的步骤1.9 中, 使方向与 LP 镜像表面的向量法线一致. <img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg">(D) 三点弯曲配置示意图, 显示骨针和测量的位移和的变形. <img alt="Equation 49" src="/files/ftp_upload/56571/56571eq49.jpg"> </img> <img alt="Equation 50" src="/files/ftp_upload/56571/56571eq50.jpg"> </img><a href="//ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56571/56571fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
通过对海洋海绵Euplectella 蚯蚓6、7中的骨骼元素执行三点弯曲测试,演示了该设备的功能.这海绵的骨架是一个组装的花丝, 称为针 (请参见图 2A)。针是≈50µm 厚, 主要由二氧化硅6组成。Biosilica-based 针是在属于 Demospongiae、Homoscleromorpha 和 Hexactinellida 类的海绵中发现的。海绵, 如E. 蚯蚓, 属于类 Hexactinellida 也被称为 "玻璃海绵"。虽然玻璃海绵的针主要由二氧化硅组成, 它已经表明, 二氧化硅往往包含一个有机基质组成的胶原蛋白17,18或甲壳素19,20,21. 此有机基质在二氧化硅矿中起重要作用18,20。此外, 在一些针, 有机基质也可作为一个模板的矿钙的22。除了在二氧化硅中分布外, 有机基质还可以形成不同的层, 将骨针的二氧化硅分成同心、圆柱形的颗粒6,23。结果表明, 这种同心、层状结构会影响针的变形行为6,7,8,24,25,,26.因此, 针的力学性质是由他们的化学组合 (i. e., 硅蛋白复合物的化学结构) 和他们的建筑学27。玻璃海绵针的化学结构和结构仍在调查中24,28,29。
E. 蚯蚓中的大多数针都被粘合在一起, 形成一个僵硬的骨骼笼。然而, 在骨架的底部有一簇非常长的 (≈10厘米) 针称为锚针 (请参见图 2a)。我们描述了在锚针的小段上执行三点弯曲试验的协议。
在协议的步骤 1中, 描述了 custom-built 机械测试装置组件的装配和对准过程。协议的步骤 2和4提供了用于生成用于在弯曲测试中计算力和位移的校准数据的说明。在步骤 3中介绍了准备骨针节并将其装入测试夹具所采取的步骤。在骨针节上进行弯曲测试的过程在步骤 5中介绍。最后, 在代表性结果 <img alt="Equation 3" src="/files/ftp_upload/56571/56571eq3.jpg">部分中, 在步骤 2和<img alt="Equation 2" src="/files/ftp_upload/56571/56571eq2.jpg"> 4中获得的校准数据与在步骤 5中获得的弯曲测试数据一起使用和。
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56571/56571fig2.jpg"> 
图 2: 剖切和检查E. 蚯蚓针的过程.(A) E. 蚯蚓的骨架。一簇独立的锚针显示在骨架的底部。刻度条是〜 25 mm (B) 一个单一的锚骨针是固定在显微镜幻灯片上使用 #00000 红色紫貂刷和切片使用刀片。刻度线为 ~ 12 mm (C), 在样品台上的沟槽上放置了一个蚯蚓骨针的部分。沟槽边缘和沟槽脊分别以蓝绿色和橙色突出显示。骨针被推向沟槽脊, 以确保其轴线垂直于沟槽边缘。(D) 一个骨针的显微图像, 它通过了协议的步骤 3.4中描述的检查过程, 它描述了如何确定骨针节是否已损坏并应丢弃。(E) 一个骨针的显微图像, 其中包含许多裂缝, 并且缺少大量的二氧化硅层, 这将使该协议的步骤 3.4中描述的检查过程失败。缩放条形图 = 250 µm (C)、100µm (D) 和100µm (E)。<a href="//ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56571/56571fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

<table>
	<tbody>
		<tr>
			<td>TMC 36&#34; x 48&#34; isolation table with 4&#34; CleanTop breadboard</td>
			<td>TMC</td>
			<td>63-563</td>
			<td>Isolation Table</td>
		</tr>
		<tr>
			<td>Diffeential Screw Adjuster</td>
			<td>Thorlabs</td>
			<td>DAS110</td>
			<td>For stage leveling plate</td>
		</tr>
		<tr>
			<td>1&#34; Travel Micrometer Head with 0.001&#34; Graduations</td>
			<td>Thorlabs</td>
			<td>150-801ME</td>
			<td>For stage leveling plate</td>
		</tr>
		<tr>
			<td>Right-Angle Bracket for PT Series Translation Stages, 1/4&#34;-20 Mounting Holes</td>
			<td>Thorlabs</td>
			<td>PT102</td>
			<td>For microscope mount</td>
		</tr>
		<tr>
			<td>1&#34; Dovetail Translation Stage, 1/4&#34;-20 Taps</td>
			<td>Thorlabs</td>
			<td>DT25</td>
			<td>For microscope mount</td>
		</tr>
		<tr>
			<td>1&#34; Translation Stage with 1/4&#34;-170 Adjustment Screw, 1/4&#34;-20 Taps</td>
			<td>Thorlabs</td>
			<td>PT1B</td>
			<td>For microscope mount</td>
		</tr>
		<tr>
			<td>12&#34; Length, Dovetail Optical Rail</td>
			<td>Edmund Optics</td>
			<td>54-401</td>
			<td>For microscope mount</td>
		</tr>
		<tr>
			<td>2.5&#34; Width, Dovetail Carrier</td>
			<td>Edmund Optics</td>
			<td>54-404</td>
			<td>For microscope mount</td>
		</tr>
		<tr>
			<td>0.5&#34; Width, Dovetail Carrier</td>
			<td>Edmund Optics</td>
			<td>54-403</td>
			<td>For microscope mount</td>
		</tr>
		<tr>
			<td>InfiniTube Mounting C-Clamp with &#188;-20</td>
			<td>Edmund Optics</td>
			<td>57-788</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>Standard (with no In-Line Attachment), InfiniTube</td>
			<td>Edmund Optics</td>
			<td>56-125</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>Standard In-Line Attachment (Optimized at 2X-10X), InfiniTube</td>
			<td>Edmund Optics</td>
			<td>56-126</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>Mitutoyo/Achrovid Objective Adapter (M26 to M27)</td>
			<td>Edmund Optics</td>
			<td>53-787</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>5X Infinity Achrovid Microscope Objective</td>
			<td>Edmund Optics</td>
			<td>55-790</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>0.316&#34; ID, Fiber Optic Adapter SX-6</td>
			<td>Edmund Optics</td>
			<td>38-944</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>&#188;&#34; x 36&#34;, Flexible Fiber Optic Light Guide</td>
			<td>Edmund Optics</td>
			<td>42-347</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>115V, MI-150 Fiber Optic Illuminator w/IR Filter and Holder</td>
			<td>Edmund Optics</td>
			<td>55-718</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>Allied Vision Manta G-223 2/3&#34; Color CMOS Camera</td>
			<td>Edmund Optics</td>
			<td>88-452</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>Power Supply for Manta/ Guppy Pro/ Stingray/ Pike</td>
			<td>Edmund Optics</td>
			<td>68-586</td>
			<td>Microscope component</td>
		</tr>
		<tr>
			<td>1/4&#34; Travel Single Axis Translation Stage</td>
			<td>Thorlabs</td>
			<td>MS1S</td>
			<td>FODS micrometer</td>
		</tr>
		<tr>
			<td>Analog Reflectance Dependent Fiber Optic Displacement Sensor</td>
			<td>Philtec</td>
			<td>D20</td>
			<td>FODS</td>
		</tr>
		<tr>
			<td>30V, 3A DC Power Supply</td>
			<td>Agilent</td>
			<td>U8001A</td>
			<td>Power supply for DAQ and FODS</td>
		</tr>
		<tr>
			<td>14-Bit, 48 kS/s Low-Cost Multifunction DAQ</td>
			<td>National Instruments</td>
			<td>USB-6009</td>
			<td>DAQ for FODS</td>
		</tr>
		<tr>
			<td>Three Axis Motorized Translation Stage</td>
			<td>Thorlabs</td>
			<td>Thorlabs T25 XYZ-E/M</td>
			<td>Translation stage</td>
		</tr>
		<tr>
			<td>T-Cube DC Servo Motor Controller</td>
			<td>Thorlabs</td>
			<td>TDC001</td>
			<td>Motor controller for stage</td>
		</tr>
		<tr>
			<td>T-Cube Power Supply</td>
			<td>Thorlabs</td>
			<td>TPS001</td>
			<td>Power supply for motor controller</td>
		</tr>
		<tr>
			<td>National Instruments LabVIEW (2013 SP1)</td>
			<td>National Instruments</td>
			<td></td>
			<td>Used for running software</td>
		</tr>
		<tr>
			<td>National Instruments LabVIEW Vision Acquisition Software (2016)</td>
			<td>National Instruments</td>
			<td></td>
			<td>Used for running software</td>
		</tr>
		<tr>
			<td>Nikon Eclipse Ci-POL Main Body</td>
			<td>MVI</td>
			<td>MDA96000</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Nikon Pi Intermediate Tube with Analyzer Slider</td>
			<td>MVI</td>
			<td>MDB45305</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Nikon Dia-Polarizer</td>
			<td>MVI</td>
			<td>MDN11920</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Power Cord - 7&#39;6&#34;</td>
			<td>MVI</td>
			<td>79035</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Nikon P-Amh Mechanical Stage</td>
			<td>MVI</td>
			<td>MDC45000</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Nikon Lwd Achromat Condenser</td>
			<td>MVI</td>
			<td>MBL16100</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Nikon LV-NBD5BD-CH Manual Quint Nosepiece ESD</td>
			<td>MVI</td>
			<td>MBP60125</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Nikon C-TF Trinocular Tube F</td>
			<td>MVI</td>
			<td>MBB93100</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Nikon CFI 10X Eyepiece FN 22mm NC</td>
			<td>MVI</td>
			<td>MAK10110</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Nikon TU Plan Flour BD 10x Objective</td>
			<td>MVI</td>
			<td>MUE42100</td>
			<td>Polarized light microscope</td>
		</tr>
		<tr>
			<td>Venus Flower Basket Sponge</td>
			<td>Denis Brand</td>
			<td>N/A</td>
			<td>Sponge skeleton</td>
		</tr>
		<tr>
			<td>3.5X Headband Flip-Up Magnifier</td>
			<td>McMaster Carr</td>
			<td>1490T5</td>
			<td>Used for spicule sectioning</td>
		</tr>
		<tr>
			<td>&#216;1&#34; Silicon Wafer, Type P / &#60;100&#62;</td>
			<td>Ted Pella</td>
			<td>16011</td>
			<td>Used for load point mirror</td>
		</tr>
		<tr>
			<td>Low Lint Tapered Tip Cotton Swab</td>
			<td>McMaster Carr</td>
			<td>71035T31</td>
			<td>Used for cleaning LP mirror</td>
		</tr>
		<tr>
			<td>Rubber grip precision knife</td>
			<td>McMaster Carr</td>
			<td>35575A68</td>
			<td>Used for sectioning spicules</td>
		</tr>
		<tr>
			<td>Microscope Slides, frosted end, 75 x 25 x 1mm</td>
			<td>Ted Pella</td>
			<td>260409</td>
			<td>Used for sectioning spicules</td>
		</tr>
		<tr>
			<td>Sable Brushes, #00000, 0.08mm W x 4.0mm L</td>
			<td>Ted Pella</td>
			<td>11806</td>
			<td>Used for handling spicules</td>
		</tr>
		<tr>
			<td>PELCO Pro High Precision Tweezers, extra fine tips, superior finish</td>
			<td>Ted Pella</td>
			<td>5367-5NM</td>
			<td>Used for handling spicules</td>
		</tr>
		<tr>
			<td>Dual Axis Linear Scale Micrometer</td>
			<td>Edmund Optics</td>
			<td>58-608</td>
			<td>Used for calibrating the microscopes</td>
		</tr>
		<tr>
			<td>FLEX-A-TOP FT-38 CAS</td>
			<td>ESD Plastic Containers</td>
			<td>FT-38-CAS</td>
			<td>Used for storing spicules</td>
		</tr>
		<tr>
			<td>Plastic Vial Bullseye Level</td>
			<td>McMaster Carr</td>
			<td>2147A11</td>
			<td>Used for leveling the stage</td>
		</tr>
		<tr>
			<td>Analytical Balance</td>
			<td>Mettler Toledo</td>
			<td>MS105DU</td>
			<td>Used to mass calibration weights</td>
		</tr>
	</tbody>
</table>

a millimeter scale flexural testing system for measuring the mechanical properties of marine sponge spicules

许多承重生物结构 (LBBSs)-例如羽毛轴和针-是小 (和 #60; 1 毫米), 但不是微观的。测量这些 LBBSs 的弯曲行为对于了解其显著的机械功能的起源是非常重要的。
我们描述一个执行三点弯曲试验的协议, 使用 custom-built 的机械测试装置, 它可以测量从 10-5到 101 N 的力, 以及从 10-7到 10-2 m 不等的位移.该机械试验装置的主要优点是可以方便地调整不同 LBBSs 的力和位移能力。该装置的工作原理类似于原子力显微镜。即, 力是应用到 LBBS 的负载点, 附加到一个悬臂的一端。用光纤位移传感器测量负载点位移, 并利用实测悬臂刚度将其转换为力。该装置的受力范围可通过使用不同刚度的悬臂来调节。
通过对海洋海绵Euplectella 蚯蚓的骨架元素执行三点弯曲试验, 演示了该设备的功能。骨骼元素--称为针--是直径约50µm 的二氧化硅纤维。我们描述了校准机械测试装置的程序, 在一个≈1.3 mm 跨度的三点弯曲夹具上安装针, 并执行弯曲试验。测量了施加于骨针的力及其在施加力位置的挠度。

任何机械试验的最基本的输出是对试样施加的力的大小和在施加力的位置的位移。在三点弯曲试验的情况下, 目标是获取由 lpt、和在方向中的 lpt 下的试样截面位移所应用的力的大小. <img alt="Equation 13" src="/files/ftp_upload/56571/56571eq13.jpg"> </img> <img alt="Equation 4" src="/files/ftp_upload/56571/56571eq4.jpg"> <img alt="Equation 14" src="/files/ftp_upload/56571/56571eq14.jpg"> </img>但是, 对于此处描述的机械测试设备, 必须执行几个后续步骤, 才能将从协议步骤2、4和5中获得的输出数据转换为所需的-数据. <img alt="Equation 13" src="/files/ftp_upload/56571/56571eq13.jpg"> </img> <img alt="Equation 14" src="/files/ftp_upload/56571/56571eq14.jpg">从三点弯曲试验获得的数据文件为: 1) 电压位移插值文件;2) 力校验文件;和 3) 弯曲测试文件。表 1中显示了度量和派生数量的摘要。
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>符号</td>
			<td colspan="4">定义</td>
		</tr>
		<tr>
			<td>Nh</td>
			<td colspan="4">电压-位移插值输出文件中的电压值数</td>
		</tr>
		<tr>
			<td>Vh</td>
			<td colspan="4">协议步骤4中的测量电压值</td>
		</tr>
		<tr>
			<td>σVh</td>
			<td colspan="4">Vh 的标准偏差</td>
		</tr>
		<tr>
			<td>zsh</td>
			<td colspan="4">在协议步骤4中测量的阶段位置</td>
		</tr>
		<tr>
			<td>Nc</td>
			<td colspan="4">力校准输出文件中的力测量数</td>
		</tr>
		<tr>
			<td>Fc</td>
			<td colspan="4">在协议的步骤2中使用校准权重的强制</td>
		</tr>
		<tr>
			<td>Vc</td>
			<td colspan="4">协议步骤2中的测量电压值</td>
		</tr>
		<tr>
			<td>σVc</td>
			<td colspan="4">标准偏差Vc </td>
		</tr>
		<tr>
			<td>zlc</td>
			<td colspan="4">LP 在使用Vh 和Vc 计算的协议的步骤2中的位置</td>
		</tr>
		<tr>
			<td>wlc</td>
			<td colspan="4">从zlc 计算的协议步骤2中的 LP 的移位</td>
		</tr>
		<tr>
			<td>Nt</td>
			<td colspan="4">弯曲试验输出文件中的力和位移测量数</td>
		</tr>
		<tr>
			<td>zst</td>
			<td colspan="4">该阶段在《议定书》5步中的地位</td>
		</tr>
		<tr>
			<td>wst</td>
			<td colspan="4">《议定书》步骤5中阶段的位移</td>
		</tr>
		<tr>
			<td>Vt</td>
			<td colspan="4">协议步骤5中的测量电压值</td>
		</tr>
		<tr>
			<td>σVt</td>
			<td colspan="4">标准偏差Vt </td>
		</tr>
		<tr>
			<td>zlt</td>
			<td colspan="4">LP 在使用Vh 和Vt 计算的协议的步骤5中的位置</td>
		</tr>
		<tr>
			<td>wlt</td>
			<td colspan="4">从zlt 计算的协议步骤5中 LP 的移位</td>
		</tr>
		<tr>
			<td>f</td>
			<td colspan="4">LP 在从zlt 计算的协议的步骤5中应用的强制</td>
		</tr>
		<tr>
			<td>w0</td>
			<td colspan="4">协议步骤5中 LP 下骨针截面的位移</td>
		</tr>
	</tbody>
</table>
表 1: 在《议定书》步骤2、4和5中测量的数量所用符号的摘要, 并在代表性结果部分计算。
电压位移插值文件的目的是将测量的 FODS 输出电压与 LPT 位移联系起来。这是通过将 LPT 与转换阶段的刚性耦合来完成的, 以便在方向中移动阶段时, 轴阶段位置的更改等于 lpt 位移 (协议<img alt="Equation 1" src="/files/ftp_upload/56571/56571eq1.jpg">的步骤 4 ). <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"> </img>电压位移插值文件包含一组点, 其中是平均 FODS 输出电压, 其采样速率为1000年赫兹, 是100电压的相关标准偏差. <img alt="Equation 15" src="/files/ftp_upload/56571/56571eq15.jpg"> </img> <img alt="Equation 16" src="/files/ftp_upload/56571/56571eq16.jpg"> <img alt="Equation 17" src="/files/ftp_upload/56571/56571eq17.jpg">度量值, 是轴阶段位置, 是阶段置换步骤的数量 (请<img alt="Equation 18" src="/files/ftp_upload/56571/56571eq18.jpg">参见图 6 (B)). <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"> </img> <img alt="Equation 19" src="/files/ftp_upload/56571/56571eq19.jpg">
力校准文件允许测量悬臂刚度, 使 lp 位移可以用来计算 lp 所施加的力的大小。强制校准文件包含一组点, 其中是平均 FODS 输出电压, 其采样速率为1000年赫兹, 是100电压测量的相关标准偏差, <img alt="Equation 20" src="/files/ftp_upload/56571/56571eq20.jpg"> </img> <img alt="Equation 21" src="/files/ftp_upload/56571/56571eq21.jpg"> <img alt="Equation 22" src="/files/ftp_upload/56571/56571eq22.jpg"> <img alt="Equation 23" src="/files/ftp_upload/56571/56571eq23.jpg">是由 LPT 上的权重施加的力, 是使用的校准权重的数量. <img alt="Equation 24" src="/files/ftp_upload/56571/56571eq24.jpg">注意, 有两个点比有校准权重, 因为第一个点是测量零应用力和第二个点的力量施加的线钩单独。
最后, 弯曲测试文件用于计算和. <img alt="Equation 14" src="/files/ftp_upload/56571/56571eq14.jpg"> <img alt="Equation 13" src="/files/ftp_upload/56571/56571eq13.jpg"> </img>它包含一组点, 其中是平均 FODS 输出电压, 其采样速率为1000年赫兹, 是100电压测量的相关标准偏差, 为<img alt="Equation 25" src="/files/ftp_upload/56571/56571eq25.jpg"> </img> <img alt="Equation 26" src="/files/ftp_upload/56571/56571eq26.jpg"> <img alt="Equation 27" src="/files/ftp_upload/56571/56571eq27.jpg"> <img alt="Equation 28" src="/files/ftp_upload/56571/56571eq28.jpg"> <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg">-轴阶段位置和是重兵<img alt="Equation 29" src="/files/ftp_upload/56571/56571eq29.jpg">在弯曲试验过程中阶段位移台阶的 r。
首先, 通过使用 set 将值映射到值, 通过线性插值, 找到了在强制校准期间的 LPT 位置的组件. <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"> <img alt="Equation 30" src="/files/ftp_upload/56571/56571eq30.jpg"> </img> <img alt="Equation 31" src="/files/ftp_upload/56571/56571eq31.jpg"> <img alt="Equation 21" src="/files/ftp_upload/56571/56571eq21.jpg"> </img> <img alt="Equation 32" src="/files/ftp_upload/56571/56571eq32.jpg">LPT 移位的组件由、提供. <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"> <img alt="Equation 33" src="/files/ftp_upload/56571/56571eq33.jpg"> </img> <img alt="Equation 34" src="/files/ftp_upload/56571/56571eq34.jpg"> </img>由于与悬臂的长度相比, LPT 位移很小, 所以和之间的关系似乎是线性的. <img alt="Equation 23" src="/files/ftp_upload/56571/56571eq23.jpg"> <img alt="Equation 35" src="/files/ftp_upload/56571/56571eq35.jpg">因此, 悬臂刚度可以通过拟合一条线来计算数据并计算斜率,. <img alt="Equation 36" src="/files/ftp_upload/56571/56571eq36.jpg"> <img alt="Equation 37" src="/files/ftp_upload/56571/56571eq37.jpg"> </img>有代表性的点集及其相应的拟合行<img alt="Equation 36" src="/files/ftp_upload/56571/56571eq36.jpg">显示在图 6A中。弯曲试验用悬臂梁的刚度为90.6 ±0.3 米/秒。
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/56571/56571fig6.jpg"> 
图 6: 三点弯曲试验的代表性结果.(A) 在协议的步骤 2中获得的强制和置换数据 (灰色) 以及用于估计悬臂刚度的线性拟合 (蓝色)。(B) 在电压-位移插值输出文件中包含的数据的代表性示例。对于测量的 FODS 输出电压,, 可以通过线性插值获得舞台的位置. <img alt="Equation 51" src="/files/ftp_upload/56571/56571eq51.jpg"> </img> <img alt="Equation 52" src="/files/ftp_upload/56571/56571eq52.jpg"> </img>这用于在弯曲测试期间测量悬臂位移. <img alt="Equation 50" src="/files/ftp_upload/56571/56571eq50.jpg"> </img>(C) 3 不同的E. 蚯蚓锚针的典型力-位移响应从成功的三点弯曲测试。(D) 一个不成功的三点弯曲试验的力-位移响应。该曲线的非线性表明, 骨针没有正确地坐在样品的阶段和滑动或重新定向后, 最初的接触是与 LPT。<a href="//ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/56571/56571fig6large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
接下来, 通过使用 set 将值映射到值 (通过线性插值), 可以找到该 LPT 在弯曲测试期间的位置的组件. <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"> <img alt="Equation 38" src="/files/ftp_upload/56571/56571eq38.jpg"> </img> <img alt="Equation 31" src="/files/ftp_upload/56571/56571eq31.jpg"> <img alt="Equation 26" src="/files/ftp_upload/56571/56571eq26.jpg"> <img alt="Equation 39" src="/files/ftp_upload/56571/56571eq39.jpg">在弯曲测试过程中, LPT 位移的组件由、提供. <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"> <img alt="Equation 40" src="/files/ftp_upload/56571/56571eq40.jpg"> </img> <img alt="Equation 41" src="/files/ftp_upload/56571/56571eq41.jpg"> </img>在弯曲测试期间, 阶段置换的组件由提供. <img alt="Equation 5" src="/files/ftp_upload/56571/56571eq5.jpg"> <img alt="Equation 42" src="/files/ftp_upload/56571/56571eq42.jpg"> </img>
由于 LPT 和骨针在弯曲测试的整个过程中都处于接触中, 因此骨针位移, 由<img alt="Equation 43" src="/files/ftp_upload/56571/56571eq43.jpg">
<img alt="Equation 44" src="/files/ftp_upload/56571/56571eq44.jpg">(1)
而由 LPT () 应用的力是<img alt="Equation 45" src="/files/ftp_upload/56571/56571eq45.jpg"> </img>
<img alt="Equation 46" src="/files/ftp_upload/56571/56571eq46.jpg">(2)
需要注意的是, 由于 set 用于通过插值获取和值, 因此和的值必须在范围内. <img alt="Equation 31" src="/files/ftp_upload/56571/56571eq31.jpg"> <img alt="Equation 32" src="/files/ftp_upload/56571/56571eq32.jpg"> <img alt="Equation 39" src="/files/ftp_upload/56571/56571eq39.jpg"> <img alt="Equation 47" src="/files/ftp_upload/56571/56571eq47.jpg"> <img alt="Equation 26" src="/files/ftp_upload/56571/56571eq26.jpg"> <img alt="Equation 16" src="/files/ftp_upload/56571/56571eq16.jpg"> </img>通过在协议的步骤 2、 4和5中为启动电压和高电压停止值设置适当的值来确保这一点。
图 6C显示三代表针的强制位移曲线。对于在三点弯曲中加载的细长的线性弹性结构, 将<img alt="Equation 13" src="/files/ftp_upload/56571/56571eq13.jpg">与30的小数值的线性增加. <img alt="Equation 14" src="/files/ftp_upload/56571/56571eq14.jpg"> <img alt="Equation 14" src="/files/ftp_upload/56571/56571eq14.jpg">非线性的-曲线为小<img alt="Equation 13" src="/files/ftp_upload/56571/56571eq13.jpg"> </img>(如 <img alt="Equation 14" src="/files/ftp_upload/56571/56571eq14.jpg"> , <img alt="Equation 14" src="/files/ftp_upload/56571/56571eq14.jpg">请参见图 6D) 通常建议骨针在采样阶段不能正确就位。在这种情况下, 应停止测试, 并在示例阶段 (协议的步骤 3.6 ) 重新定位骨针。
为了确保和测量的足够精度, 弯曲测试过程中的总电压变化,, 应至少为 1 v. <img alt="Equation 13" src="/files/ftp_upload/56571/56571eq13.jpg"> <img alt="Equation 14" src="/files/ftp_upload/56571/56571eq14.jpg"> <img alt="Equation 48" src="/files/ftp_upload/56571/56571eq48.jpg"> </img>如果总的电压变化小于 1 V, 一个更加兼容的悬臂应该是 selected

Watch this Scientific Journal Video about A Millimeter Scale Flexural Testing System for Measuring the Mechanical Properties of Marine Sponge Spicules at JoVE.com

A Millimeter Scale Flexural Testing System for Measuring the Mechanical Properties of Marine Sponge Spicules

我们提出了一个协议, 执行三点弯曲试验的毫米规模纤维使用 custom-built 机械测试装置。该装置可以测量的力量范围从20µN 到 10 N, 因此可以容纳各种纤维大小。

测量海洋海绵针力学性能的毫米尺度弯曲试验系统

Many load bearing biological structures (LBBSs)&#8212;such as feather rachises and spicules&#8212;are small (&#60;1 mm) but not microscopic. Measuring the ...

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Internal Forces

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8.4K 次观看.  Brown University. 我们提出了一个协议, 执行三点弯曲试验的毫米规模纤维使用 custom-built 机械测试装置。该装置可以测量的力量范围从20µN 到 10 N, 因此可以容纳各种纤维大小。

视频: A Millimeter Scale Flexural Testing System for Measuring the Mechanical Properties of Marine Sponge Spicules

Quantifying the Mechanical Properties of the Endothelial Glycocalyx with Atomic Force Microscopy

Our understanding of the interaction of leukocytes and the vessel wall during leukocyte capture is limited by an incomplete understanding of the mechanical properties of the endothelial surface layer. It is known that adhesion molecules on leukocytes are distributed non-uniformly relative to surface topography 3, that topography limits adhesive bond formation with other surfaces 9, and that physiological contact forces (&asymp; 5.0 &minus; 10.0 pN per microvillus) can compress the microvilli to as little as a third of their resting length, increasing the accessibility of molecules to the opposing surface 3, 7. We consider the endothelium as a two-layered structure, the relatively rigid cell body, plus the glycocalyx, a soft protective sugar coating on the luminal surface 6. It has been shown that the glycocalyx can act as a barrier to reduce adhesion of leukocytes to the endothelial surface 4. In this report we begin to address the deformability of endothelial surfaces to understand how the endothelial mechanical stiffness might affect bond formation. Endothelial cells grown in static culture do not express a robust glycocalyx, but cells grown under physiological flow conditions begin to approximate the glycocalyx observed in vivo 2. The modulus of the endothelial cell body has been measured using atomic force microscopy (AFM) to be approximately 5 to 20 kPa 5. The thickness and structure of the glycocalyx have been studied using electron microscopy 8, and the modulus of the glycocalyx has been approximated using indirect methods, but to our knowledge, there have been no published reports of a direct measurement of the glycocalyx modulus in living cells. In this study, we present indentation experiments made with a novel AFM probe on cells that have been cultured in conditions to maximize their glycocalyx expression to make direct measurements of the modulus and thickness of the endothelial glycocalyx.

The mechanical characteristics of endothelial glycocalyx were measured by indentation using micron sized spheres on AFM cantilevers. Endothelial cells were cultured in a custom chamber under physiological flow conditions to induce glycocalyx expression. Data were analyzed using a thin film model to determine the glycocalyx thickness and modulus.

量化的内皮细胞糖复合物的力学性能，用原子力显微镜

Our  understanding of the interaction of leukocytes and the vessel wall during  leukocyte capture is limited by an incomplete understanding of the ...

科研

生物工程

Design of a Biaxial Mechanical Loading Bioreactor for Tissue Engineering

We designed a loading device that is capable of applying uniaxial or biaxial mechanical strain to a tissue engineered biocomposites fabricated for transplantation. While the device primarily functions as a bioreactor that mimics the native mechanical strains, it is also outfitted with a load cell for providing force feedback or mechanical testing of the constructs. The device subjects engineered cartilage constructs to biaxial mechanical loading with great precision of loading dose (amplitude and frequency) and is compact enough to fit inside a standard tissue culture incubator. It loads samples directly in a tissue culture plate, and multiple plate sizes are compatible with the system. The device has been designed using components manufactured for precision-guided laser applications. Bi-axial loading is accomplished by two orthogonal stages. The stages have a 50 mm travel range and are driven independently by stepper motor actuators, controlled by a closed-loop stepper motor driver that features micro-stepping capabilities, enabling step sizes of less than 50 nm. A polysulfone loading platen is coupled to the bi-axial moving platform. Movements of the stages are controlled by Thor-labs Advanced Positioning Technology (APT) software. The stepper motor driver is used with the software to adjust load parameters of frequency and amplitude of both shear and compression independently and simultaneously. Positional feedback is provided by linear optical encoders that have a bidirectional repeatability of 0.1 &mu;m and a resolution of 20 nm, translating to a positional accuracy of less than 3 &mu;m over the full 50 mm of travel. These encoders provide the necessary position feedback to the drive electronics to ensure true nanopositioning capabilities. In order to provide the force feedback to detect contact and evaluate loading responses, a precision miniature load cell is positioned between the loading platen and the moving platform. The load cell has high accuracies of 0.15% to 0.25% full scale.

We designed a novel mechanical loading bioreactor that can apply uniaxial or biaxial mechanical strain to a cartilage biocomposite prior to transplantation into an articular cartilage defect.

组织工程生物反应器的双轴机械装载设计

We  designed a loading device that is capable of applying uniaxial or biaxial  mechanical strain to a tissue engineered biocomposites fabricated for  ...

Measuring the Mechanical Properties of Living Cells Using Atomic Force Microscopy

Mechanical properties of cells and extracellular matrix (ECM) play important roles in many biological processes including stem cell differentiation, tumor formation, and wound healing. Changes in stiffness of cells and ECM are often signs of changes in cell physiology or diseases in tissues. Hence, cell stiffness is an index to evaluate the status of cell cultures. Among the multitude of methods applied to measure the stiffness of cells and tissues, micro-indentation using an Atomic Force Microscope (AFM) provides a way to reliably measure the stiffness of living cells. This method has been widely applied to characterize the micro-scale stiffness for a variety of materials ranging from metal surfaces to soft biological tissues and cells. The basic principle of this method is to indent a cell with an AFM tip of selected geometry and measure the applied force from the bending of the AFM cantilever. Fitting the force-indentation curve to the Hertz model for the corresponding tip geometry can give quantitative measurements of material stiffness. This paper demonstrates the procedure to characterize the stiffness of living cells using AFM. Key steps including the process of AFM calibration, force-curve acquisition, and data analysis using a MATLAB routine are demonstrated. Limitations of this method are also discussed.

This paper demonstrates a protocol to characterize the mechanical properties of living cells by means of microindentation using an Atomic Force Microscope (AFM).

使用原子力显微镜测量活细胞的力学性能

Mechanical  properties of cells and extracellular matrix (ECM) play important roles in many  biological processes including stem cell differentiation, ...

Robotic Production of Cancer Cell Spheroids with an Aqueous Two-phase System for Drug Testing

Cancer cell spheroids present a relevant in vitro model of avascular tumors for anti-cancer drug testing applications. A detailed protocol for producing both mono-culture and co-culture spheroids in a high throughput 96-well plate format is described in this work. This approach utilizes an aqueous two-phase system to confine cells into a drop of the denser aqueous phase immersed within the second aqueous phase. The drop rests on the well surface and keeps cells in close proximity to form a single spheroid. This technology has been adapted to a robotic liquid handler to produce size-controlled spheroids and expedite the process of spheroid production for compound screening applications. Spheroids treated with a clinically-used drug show reduced cell viability with increase in the drug dose. The use of a standard micro-well plate for spheroid generation makes it straightforward to analyze viability of cancer cells of drug-treated spheroids with a micro-plate reader. This technology is straightforward to implement both robotically and with other liquid handling tools such as manual pipettes.

A protocol for robotic printing of cancer cell spheroids in a high throughput 96-well plate format using an aqueous two-phase system is presented.

癌症细胞球体机器人生产与药物测试的双水相系统

Cancer cell spheroids present a relevant in vitro model of avascular tumors for anti-cancer drug testing applications. A detailed protocol for producing ...

In Situ Mapping of the Mechanical Properties of Biofilms by Particle-tracking Microrheology

Bacterial cells are able to form surface-attached biofilm communities known as biofilms by encasing themselves in extracellular polymeric substances (EPS). The EPS serves as a physical and protective scaffold that houses the bacterial cells and consists of a variety of materials that includes proteins, exopolysaccharides and DNA. The composition of the EPS may change, which remodels the mechanic properties of the biofilm to further develop or support alternative biofilm structures, such as streamers, as a response to environmental cues. Despite this, there are little quantitative descriptions on how EPS components contribute to the mechanical properties and function of biofilms. Rheology, the study of the flow of matter, is of particular relevance to biofilms as many biofilms grow in flow conditions and are constantly exposed to shear stress. It also provides measurement and insight on the spreading of the biofilm on a surface. Here, particle-tracking microrheology is used to examine the viscoelasticity and effective crosslinking roles of different matrix components in various parts of the biofilm during development. This approach allows researchers to measure mechanic properties of biofilms at the micro-scale, which might provide useful information for controlling and engineering biofilms.

In Situ Mapping of the Mechanical Properties of Biofilms by Particle-tracking Microrheology

Particle-tracking microrheology investigates the viscoelasticity of materials. Here, the technique is used to determine the viscoelasticity, creep compliance and effective crosslinking roles of different matrix components of a bacterial biofilm. The matrix consists of polymeric substances secreted by the bacteria and its components determine biofilm structure and mechanical properties.

在生物膜的力学性能原位制图粒子追踪Microrheology

Bacterial cells are able to form surface-attached biofilm communities known as biofilms by encasing themselves in extracellular polymeric substances ...

A Protocol for Bioinspired Design: A Ground Sampler Based on Sea Urchin Jaws

Bioinspired design is an emerging field that takes inspiration from nature to develop high-performance materials and devices. The sea urchin mouthpiece, known as the Aristotle's lantern, is a compelling source of bioinspiration with an intricate network of musculature and calcareous teeth that can scrape, cut, chew food and bore holes into rocky substrates. We describe the bioinspiration process as including animal observation, specimen characterization, device fabrication and mechanism bioexploration. The last step of bioexploration allows for a deeper understanding of the initial biology. The design architecture of the Aristotle's lantern is analyzed with micro-computed tomography and individual teeth are examined with scanning electron microscopy to identify the microstructure. Bioinspired designs are fabricated with a 3D printer, assembled and tested to determine the most efficient lantern opening and closing mechanism. Teeth from the bioinspired lantern design are bioexplored via finite element analysis to explain from a mechanical perspective why keeled tooth structures evolved in the modern sea urchins we observed. This circular approach allows for new conclusions to be drawn from biology and nature.

A protocol for bioinspired design is described for a sampling device based on the jaws of a sea urchin. The bioinspiration process includes observing the sea urchins, characterizing the mouthpiece, 3D printing of the teeth and their assembly, and bioexploring the tooth structure.

基于海胆大白鲨A接地采样:仿生为设计一个协议

Bioinspired design is an emerging field that takes inspiration from nature to develop high-performance materials and devices. The sea urchin mouthpiece, ...

Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing

Minimization and management of membrane fouling is a formidable challenge in diverse industrial processes and other practices that utilize membrane technology. Understanding the fouling process could lead to optimization and higher efficiency of membrane based filtration. Here we show the design and fabrication of an automated three-dimensionally (3-D) printed microfluidic cross-flow filtration system that can test up to 4 membranes in parallel. The microfluidic cells were printed using multi-material photopolymer 3-D printing technology, which used a transparent hard polymer for the microfluidic cell body and incorporated a thin rubber-like polymer layer, which prevents leakages during operation. The performance of ultrafiltration (UF), and nanofiltration (NF) membranes were tested and membrane fouling could be observed with a model foulant bovine serum albumin (BSA). Feed solutions containing BSA showed flux decline of the membrane. This protocol may be extended to measure fouling or biofouling with many other organic, inorganic or microbial containing solutions. The microfluidic design is especially advantageous for testing materials that are costly or only available in small quantities, for example polysaccharides, proteins, or lipids due to the small surface area of the membrane being tested. This modular system may also be easily expanded for high throughput testing of membranes.&#160;

Design and fabrication of a three-dimensionally (3-D) printed microfluidic cross-flow filtration system is demonstrated. The system is used to test performance and observe fouling of ultrafiltration and nanofiltration (thin film composite) membranes.

超滤/纳滤膜性能测试三维印刷微流控横流系统

Minimization and management of membrane fouling is a formidable challenge in diverse industrial processes and other practices that utilize membrane ...

A Performance-testing Platform for a Conduction Micropump with an FR-4 Copper-clad Electrode Plate

Here, a conduction micropump with symmetric planar electrode pairs prepared on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) is fabricated. It is used to investigate the influence of chamber dimensions on the performance of a conduction micropump and to determine the reliability of the conduction pump when acetone is used as the working fluid. A testing platform is set up to evaluate conduction micropump performance under different conditions. When the chamber height is 0.2 mm, the pump pressure reaches its peak value.

This paper presents a protocol for the fabrication of a conduction micropump using symmetric planar electrodes on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) to test the influence of chamber dimensions on the performance of a conduction micropump.

FR-4 铜包电极板导电微泵性能测试平台

Here, a conduction micropump with symmetric planar electrode pairs prepared on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) is ...

Rigid Embedding of Fixed and Stained, Whole, Millimeter-Scale Specimens for Section-free 3D Histology by Micro-Computed Tomography

For over a hundred years, the histological study of tissues has been the gold standard for medical diagnosis because histology allows all cell types in every tissue to be identified and characterized. Our laboratory is actively working to make technological advances in X-ray micro-computed tomography (micro-CT) that will bring the diagnostic power of histology to the study of full tissue volumes at cellular resolution (i.e., an X-ray Histo-tomography modality). Toward this end, we have made targeted improvements to the sample preparation pipeline. One key optimization, and the focus of the present work, is a straightforward method for rigid embedding of fixed and stained millimeter-scale samples. Many of the published methods for sample immobilization and correlative micro-CT imaging rely on placing the samples in paraffin wax, agarose, or liquids such as alcohol. Our approach extends this work with custom procedures and the design of a 3-dimensional printable apparatus to embed the samples in an acrylic resin directly into polyimide tubing, which is relatively transparent to X-rays. Herein, sample preparation procedures are described for the samples from 0.5 to 10 mm in diameter, which would be suitable for whole zebrafish larvae and juveniles, or other animals and tissue samples of similar dimensions. As proof of concept, we have embedded the specimens from Danio, Drosophila, Daphnia, and a mouse embryo; representative images from 3-dimensional scans for three of these samples are shown. Importantly, our methodology leads to multiple benefits including rigid immobilization, long-term preservation of laboriously-created resources, and the ability to re-interrogate samples.

We developed protocols and designed a custom apparatus to enable embedding of millimeter-scale specimens. We present sample preparation procedures with an emphasis on embedding in acrylic resin and polyimide tubing to achieve rigid immobilization and long-term storage of specimens for the interrogation of tissue architecture and cell morphology by micro-CT.

用微计算机断层扫描法对无节段3D 组织学进行固定染色、全尺寸、毫米度试样的刚性嵌入

For over a hundred years, the histological study of tissues has been the gold standard for medical diagnosis because histology allows all cell types in ...

Automated Counterflow Centrifugal System for Small-Scale Cell Processing

Successful commercialization of gene and cell-based therapies requires manufacturing processes that are cost-effective and scalable. Buffer exchange and product concentration are essential components for most manufacturing processes. However, at the early stages of product development, these steps are often performed manually. Manual dead-end centrifugation for buffer exchange is labor-intensive, costly, and not scalable. A closed automated system can effectively eliminate this laborious step, but implementation can be challenging. Here, we describe a newly developed cell processing device that is suitable for small- to medium-scale cell processing and aims to bridge the gap between manual processing and large-scale automation. This protocol can be easily applied to various cell types and processes by modifying the flow rate and centrifugation speed. Our protocol demonstrated high cell recovery with shorter processing times in comparison to the manual process. Cells recovered from the automated process also maintained their proliferation rates. The device can be applied as a modular component in a closed manufacturing process to accommodate steps such as buffer exchange, cell formulation, and cryopreservation.

Automation is key to upscaling and cost management in cell manufacturing. This manuscript describes the use of a counterflow centrifugal cell processing device for automating the buffer exchange and cell concentration steps for small-scale bioprocessing.

用于小型细胞处理的自动逆流离心系统

Successful commercialization of gene and cell-based therapies requires manufacturing processes that are cost-effective and scalable. Buffer exchange and ...