Ionic polymer-metal composites (IPMC) are soft actuators with potential applications in the fields of medicine and
biologically inspired robotics. Typically, an IPMC bends with approximately constant curvature when voltage is applied
to it. More complex shapes were achieved in the past by pre-shaping the actuator or by segmentation and separate
actuation of each segment. There are many applications for which fully independent control of each segment of the
IPMC is not required and the use of external wiring is objectionable. In this paper we propose two key elements needed
to create an IPMC, which can actuate into a complex curve. The first is a connection between adjacent segments, which
enables opposite curvature. This can be achieved by reversing the polarity applied on each side of the IPMC, for
example by a through-hole connection. The second key element is a variable curvature segment. The segment is
designed to bend with any fraction of its full bending ability under given electrical input by changing the overlap of
opposite charge electrodes. We demonstrated the usefulness of these key elements in two devices. One is a bi-stable
buckled IPMC beam, also used as a building block in a linear actuator device. The other one is an IPMC, actuating into
an S-shaped curve with gradually increasing curvature near the ends. The proposed method of manufacturing holds
promise for a wide range of new applications of IPMCs, including applications in which IPMCs are used for sensing.
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