Study on the Modification of Polymers for Human-gentle Sensors and Actuators

聚合物凝胶由于其独特的材料形态，作为“智能材料”而备受关注。他们也被研究在各个领域。将聚乙烯醇（PVA）水溶液冷冻缓慢解冻合成的水凝胶具有高含水量、高抗拉强度、伸长率和良好的弹性形状恢复等优异的力学性能。聚乙烯醇的聚合度为2500，皂化度为99.5 mol%。将7.5g PVA溶解于80g水中得到的溶液，在50℃下冷冻3小时，然后加热至室温10小时，再重复此冻融过程，合成水凝胶。水凝胶的含水量约为90wt%。拉伸强度为0.6MPa，断裂伸长率为130%。受外力作用而变形的水凝胶在外力释放后，其形状在短时间内恢复原状。这种恢复具有良好的持续性和可重复性。利用这些特性，制作了应变传感器和气体压力传感器进行试验。它可以使用含有电解质溶液的水凝胶应用于应变传感器和气体压力传感器。此外，含有PAA的铂丝电极的PVA水凝胶棒可以在直流作用下弯曲。这种杆是能够应用到手指的抓手作为一个灵活的执行器通过这种弯曲行为。

Polymer gels have attracted attention as the 'intelligent material'because of their peculiar material forms. They aslo have been studied in every field. The hydrogel synthesized by freezing a polyvinyl alcohol (PVA) aqueous solution and thawing it slowly has high water content, excellent mechanical properties of high tensile strength, elongation, and good shape recovery by the elasticity. Used PVA had the degree of polymerization of 2500 andthe degree of saponification of 99.5 mol%. When the solution obtained by the way that 7.5g of the PVA was dissolved in80g of water, was frozen at-50-C for 3 hours and then warmed it up to room temperature taking 10 hours, and in addition, this freezing-thawing process was repeated once again, a hydrogel was synthesized. The hydrogel had the water content of about 90wt%. The tensile strength of it was 0.6MPa and the elongation at break was 130%. The shape ofthe hydrogel which was deformed by the external force recovered in a short time when it was released from the force. This recovery had good persistence and repeatability.Applying these properties, the strain sensor and the gas pressure sensor were made for trial. it can be applied to the strain sensor and the gas pressure sensor using the hydrogel containing an electrolyte solution. Furthermore, the PVA hydrogel rod with platinum wire electrodes containing PAA can bend by applying DC.This rod is able to be applied to fingers of the gripper as a flexible acturator by this bending behavior.