A room-temperature processed parylene-patterned helical ionic polymer-metal composite spring actuator with selectable active region

作者：Feng Guo Hua^*; Zhan Zhen Hua

来源：Smart Materials and Structures, 2014, 23(4): 045002.

DOI：10.1088/0964-1726/23/4/045002

• IPMC
• Nafion
• spring
• parylene
• nickel electrode

This paper presents a novel helical ionic polymer metal composite (IPMC) spring actuator. A room-temperature fabrication process is developed to selectively grow in situ nickel metal electrode on a coiled Nafion strip, which is patterned with parylene as a masking layer to delineate the inactive region. This method allows the helical spring actuator to be shaped in a near-constant temperature environment and minimizes the residual stress effect on the Nafion polymer, compared to other processes using thermal treatment. The developed process ensures that short-circuiting never occurs between the outer and inner electrodes of the actuator, and the active region can be designed via parylene patterning. The motion of the fabricated spring actuator is measured, and the maximal displacement reaches 1 mm at the endpoint of the spring under a 0.1 Hz 6 V square wave actuation. A microtensile experiment is performed for characterizing the stress and strain relation. The resulting Young%26apos;s moduli of the Nafion and fabricated IPMC strips are 183 and 227 MPa, respectively. Analysis based on Castigliano%26apos;s theorem is executed to derive equations related to the moment, force output, strain energy, and displacement of an arbitrary point of the fabricated spring actuator. Results show the produced moment, force, and strain energy of the operated spring actuator are in the level of 1:5 mu N m, 300 mN, and 20-100 mu J, respectively.

• 出版日期2014-4