Miniaturized Sma/Smp Variable Stiffness Actuator Driven by the Stretchable Mwcnt/Il/Pdms Heater Electrode For Micromanipulation Robots

The miniaturized variable stiffness actuator fabricated of shape memory alloy (SMA) and shape memory polymer (SMP) was successfully driven by using the stretchable heater electrode. We obtained the thin SMP of 40 µm thickness by the hot press, eliminating the bubble and keeping its shape memory effect. The stretchable heater electrode fabricated of multi-wall carbon nanotube (MWCNT) and ionic liquid (IL) dispersed in the polydimethylsiloxane (PDMS) with the galvanic activation exhibited a high conductivity of 2.4 kΩ, which is allowable to the thermal actuation of SMP up to 60°C. As an example of the variable stiffness actuation, we demonstrated that the weight of 1 g was kept lifted up using the microarm even though energy supply was stopped. This technology could be applied for the powerful, and energy less microrobots or micromanipulators.