Actuation responsee of polyacrylate dielectric elastomers
Actuation responsee of polyacrylate dielectric elastomers
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DOI：
10.1177/104538903039260
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发表时间：
2003-12-01
影响因子：
2.7
通讯作者：
Pelrine, R
中科院分区：
文献类型：
--
作者：
Kofod, G;Sommer-Larsen, P;Pelrine, R
聚丙烯酸酯介电弹性体产生了极大的应变和弹性能量密度，表明它们对许多执行器应用是有用的。彻底了解观察到的电场响应机制的物理基础可以帮助开发改进的致动器。这种响应被认为是由于麦克斯韦应力，即应力与外加电场的二次依赖关系。在此假设的基础上，导出了执行器施加电压与测量力之间的关系式。实验数据与预期行为相符，尽管存在差异。进一步的分析表明，这些主要是由于执行器的制造不完善，尽管丙烯酸粘合剂的明显电致伸缩行为有一小部分贡献。对拉伸聚合物的介电常数的测量表明，当聚合物被拉伸时，介电常数下降，表明存在小的电伸缩效应。最后进行了击穿场的测量。这些也显示出对菌株的依赖性。在非应变状态下，击穿场为20 MV/m，当应变为500 × 500%时，击穿场增大到218 MV/m。这种大幅度的增加可能在执行器设计中证明是重要的。
Polyacrylate dielectric elastomers have yielded extremely large strain and elastic energy density suggesting that they are useful for many actuator applications. A thorough understanding of the physics underlying the mechanism of the observed response to an electric field can help develop improved actuators. The response is believed to be due to Maxwell stress, a quadratic dependence of the stress upon applied electric field. Based on this supposition, an equation relating the applied voltage to the measured force from an actuator was derived. Experimental data fit with the expected behavior, though there are discrepancies. Further analysis suggests that these arise mostly from imperfect manufacture of the actuators, though there is a small contribution from an explicitly electrostrictive behavior of the acrylic adhesive. Measurements of the dielectric constant of stretched polymer reveal that the dielectric constant drops, when the polymer is strained, indicating the existence of a small electrostrictive effect. Finally, measurements of the electric breakdown field were made. These also show a dependence upon the strain. In the unstrained state the breakdown field is 20 MV/m, which grows to 218 MV/m at 500 x 500% strain. This large increase could prove to be of importance in actuator design.