Liquid-Metal/Nd2Fe14B/Ecoflex Composite Soft Robots and Their Electric Signal Transmission using Non-Contact Tentacles

Signal transmission between rigid robots is usually realized through rigid electronic components like coil or circuit board. However, these rigid electronic units are difficult to be used in fully flexible soft robots because of the mismatch of Young's modulus. Liquid metal (LM), as a flexible fluid with superior electric conductivity, can be served as the alternative material for rigid electronic units to realize signal transmission in fully flexible soft robots. Herein, a fully flexible soft robot is fabricated, which is mainly consists of two functional units: the soft tentacle integrated with liquid metal spiral wire and the body prepared by Nd2Fe14B magnetic powders/Ecoflex composites. The fully flexible soft robot can not only transmit electric signals based on electromagnetic induction but also be actuated by an external magnetic field to form diverse signal transmission pathways. Related mechanisms of transmitting electric signal and driving are studied by Maxwell numerical simulation. Driven by an external magnetic field, three soft robots are capable to constitute two different pathways to transmit electric signals to the oscilloscope. It is believed that the integration of LM into the magnetic composites provides an open perspective to realize the signal transmission in fully flexible soft robot and favors the development of multifunctional soft robot.