Bioinspiration and working principle of FEDEA. Bioinspiration and working principle of FEDEA. (A) Photograph of leptocephalus (eel larva; length, about 400 mm) swimming underwater. Reprinted from Miller et al. (59), with permission from the authors. (B) Working principle of FEDEA bimorph module (not to scale): For bidirectional actuators, we make two DEAs from three layers of an acrylic elastomer adhesive. We created the active areas of the actuators by selectively passivating the surfaces of the adhesive with a powder, which allowed the conductive fluid to enter from the tubing and cover the active area. We connected the actuator to the high voltage lead of the power supply through the silicone tubing. Application of a voltage in one of the fluid chambers with respect to the external fluid induced Maxwell stress in the dielectric, inducing a bending motion away from the actuated side. Caleb Christianson et al. Sci. Robotics 2018;3:eaat1893 Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works