An Electrothermal and Magnetic Dual-Modal Actuator toward Soft Self-Sensing Robots

Soft actuators with good flexibility, high stability, and excellent controllability have attracted extensive attention. However, dual-modal smart self-perception actuator with contact and noncontact actuating mode remains a challenge. Notably, soft actuators with in situ self-sensing monitoring capabilities have gained increasing attention in smart flexible devices. This work reports a smart actuator composed of polydimethylsiloxane (PDMS)/magnetorheological elastomer (MRE)/Ag/ polyimide (PI) (PMAP), which can not only well respond to bending stimuli but also be actuated by electromagnetic dual-modal actuation. Benefiting from the nanowire-nanoflake coupling structure of conductive Ag layer, the PMAP film exhibits excellent electrical sensing and electro-heat generation behavior. The Delta R/R-0 of PMAP film increases from 5.1% to 24.7% during the bending test. Moreover, the PMAP film realizes contact electrothermal actuation due to the mismatch of thermal expansion coefficient between PDMS matrix and PI tape. Under applying a 16 s of 2 V electrothermal actuation, the bending angle of PMAP film can increase from 31.1 degrees to 219.3 degrees. Moreover, MRE matrix endows the PMAP film with noncontact magnetic deformation characteristic. This multifunctional smart flexible device integrated with in situ sensing perception and contact and noncontact dual-modal actuation performances possess high potential in electronic devices and robots.