Stimuli-Responsive Biomimetic Soft Actuator

共同研究课题的目的是利用高分子凝胶，制作能够根据湿度、离子强度或激素浓度的变化而柔和地移动或变形的仿生致动器。我们利用Nafion膜和等离子体聚合苯乙烯膜，制作了能够根据湿度变化而柔和地移动或变形的双层膜。Nafion膜由于含有磺酸基团而具有亲水性，而等离子体聚合的苯乙烯膜具有疏水性且无针孔。由于湿度的变化而在亲水层中产生的膨胀力使“不可膨胀的”疏水层弯曲。双层膜的位移随相对湿度的增加而增加，降低相对湿度后，双层膜的位移又恢复到原来的形状。在扩张过程中，响应时间约为30min，而在收缩过程中，响应时间稍长，这是首次尝试利用梯度结构的聚合物凝胶薄膜来制作仿生软驱动器。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.