A motor via printing technology
The University of Tokyo has developed a thin, soft, light-weight motor by using a printed electronics technology to print electronic circuits and a sensor.
Because all of the components of the motor are soft, it is expected to be used as an actuator for soft robots. It is one of the results of the “Strategic Creation Research Promotion Program” of the Japan Science and Technology Agency (JST).
The newly-developed soft motor contains acetone (organic solvent that boils at a low temperature), “3M Novec 7000,” in a plastic film bag. The liquid is heated by using a heater printed by using conductive ink. As a result, the liquid is vaporized/expanded in the bag, generating a driving force. When the heater is turned off, the gas is liquefied, and the motor comes back to its original shape.
The motor measures 80 x 25mm and weighs about 3g, but it generated a turning force of up to about 0.1N·m, which is equivalent to the force for bending the fifth finger, in an experiment. Its maximum operating angle is 90°. Wiring for the heater and a touch sensor were formed on a 135μm-thick PET film at the same time by using an inkjet printer and silver nano-ink.
This time, the university prototyped soft robots that resemble a butterfly, flytrap, etc in addition to a piece of paper that automatically folds up into a box. For the future, it will improve the operating speed and output of the motor by making improvements to the heating method.