Mechanotransduction can enhance cell cultures when its substrate is subjected to dynamic strain. This paper presents the design and implementation of a device that applies variable mechanical stress on a flexible biocompatible substrate. An embedded system implements a closed-loop PID control that acts on a proportional valve, which regulates the negative pressure in a chamber, generated by a miniature vacuum pump. The top cover of the chamber is a membrane that stretches according to the generated vacuum and is used for cell culture. The elastic modulus of the produced membrane was 260 kPa, similar to soft biological tissue. The deformation of the membrane was quantified by image processing and a linear pressure-deformation relationship was achieved (r and gt; 0.99). The controller was designed based on the identified valve's dynamic and it allowed variable deformations on the membrane with an amplitude of 20 % and a frequency of 2 Hz, selected by the user. The implemented device is PC independent and has a cost, size and weight almost two orders of magnitude lower than a similar commercial version.

中文翻译：

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可变机械应力下控制基底变形的细胞培养装置

当其底物受到动态应变时，机械转导可以增强细胞培养。本文介绍了一种在柔性生物相容性基板上施加可变机械应力的装置的设计和实现。嵌入式系统实现了闭环 PID 控制，该控制作用于比例阀，该阀调节由微型真空泵产生的腔室中的负压。腔室的顶盖是一层薄膜，根据产生的真空进行拉伸，用于细胞培养。制成的膜的弹性模量为 260 kPa，与软生物组织相似。膜的变形通过图像处理进行量化，并且实现了线性压力-变形关系（r 和 gt; 0.99）。控制器是根据识别出的阀门设计的 s 动态，它允许用户选择振幅为 20% 和频率为 2 Hz 的膜上的可变变形。所实现的设备独立于 PC，其成本、尺寸和重量比类似的商业版本低近两个数量级。