Materials

We have chosen to use Dielectric Elastomer Actuators (DEAs) to drive the motion of our robot. DEAs have the advantage of being completely electrically controllable, which would simplify the process of activating and coordinating the different actuators in the system using a programmable circuit. Furthermore, DEAs are lightweight compared to traditional robots with motors and heavy metallic parts, which makes for improved mobility. Lastly, DEAs are relatively easy to fabricate by hand.

We used VHB 4910 acrylic as the Dielectric Elastomer (DE) because it is an elastomer capable of producing large strains under high tension. Furthermore, it is a well-known and documented material in the field of DEAs.

Figure 7: VHB 4910 acrylic

For the compliant electrodes, we used carbon black (Sigma Aldrich) in conjunction with carbon conductive grease (MG Chemicals) because they are easy to apply by hand and do not require procedures like spray coating. This combination of conductive materials produces compliant electrodes whose conductivity is not compromised much when stretched in tension.

Figure 8: Carbon black

Figure 9: Carbon conductive grease

To connect the compliant electrodes to wires leading to the power supply, we used conductive carbon tape and copper tape. The tapes bridge the gap between the soft actuator films and the relatively rigid wires, thus reducing the risk of the actuators getting punctured by accident.

The rigid structural components of the robot were 3D printed because with 3D printing, the shape and dimensions can be customised to our requirements. Furthermore, 3D printed parts are lightweight, which is necessary to reduce impediments to motion.

Figure 10: 3D printing in progress