Touch Sensitive Dielectric Elastomer Artificial Muscles

Comb jellies are tiny sea animals that do not have brains, yet they can control the synchronous beat of hundreds of swimming paddles to navigate the water column in search of food. Waves of actuation travel down rows of paddles that run the length of the animal’s body to generate thrust. This is achieved using distributed local feedback and a simple control rule: each paddle only actuates when it is touched, and when it actuates it sweeps forward to touch the next paddle in line. No central brain is required to tell each paddle when to fire. We have created a scalable array of Dielectric Elastomer Actuators (DEA) that mimics the swimming paddles of the comb jelly and have implemented this array in a simple conveyor mechanism. Each DEA is made touch sensitive by sensing changes in its capacitance, eliminating the need for bulky external sensors. The array is inherently self-regulating and each DEA only actuates when it is touched, ensuring the conveyor automatically adjusts to the properties of the object being conveyed. This is a simple solution to a simple application, but it brings us one step closer to scalable, artificial muscle actuator arrays that might perform such useful tasks as assembly line conveyance and water propulsion. It also paves the way for more advanced systems that take into account DEA properties other than capacitance such as electrode resistance and leakage current.