Stimuli-Responsive Biomimetic Soft Actuator

这个联合研究项目的目标是用聚合物凝胶制造一种仿生致动器，它可以随着湿度、离子强度或激素浓度的变化而柔和地移动或变形。我们构建了一种响应湿度变化的双层膜，由离子膜和等离子聚合的乙烯膜组成。离子膜由于含有磺酸基团而具有亲水性，等离子体聚合的乙烯膜具有疏水性和无针孔性。由于湿度的变化，在亲水性层中产生的膨胀力使“不可膨胀”的疏水性层发生弯曲。随着相对湿度的增加，膜的位移增大，降低相对湿度后，膜的位移恢复到原来的形态。膨胀过程的响应时间约为30min，收缩过程的响应时间稍长。这是首次尝试使用具有梯度结构的聚合物凝胶膜来制造仿生软致动器。该联合项目使建立能够感知外界刺激的仿生智能驱动系统成为可能。

The objective of the joint research project is to create a biomimetic actuator with polymer gels, that moves or deforms softly in response to the change in the humidity, an ion strength or the concentration of hormones.We constructed a bilayr film in response to change in the humidity from a nafion film and plasma polymerized stirene film. The nafion film is hydrophilic owing to containing the sulfonic acid group and the plasma polymeraized stirene film is hydrophobic and pinhole free. The expansile force developed in the hydrophilic layr by changing in the humidity bends the "nonexpansible" hydrophobic layr. The displacement of the bilayr film increased as the relative humidity increased It recovered the original form after decreasing the relative humidity. The response time is about 30min in the expanding process, while it is a little longer in the contracting process.This is the first attempt to create a biomimetic soft actuator by using a polymer gel film with a gradient structure. The joint project makes it possible to establish a biomimetic intelligent actuating system capable of sensing outside stimuli.