Built in the shape of a 10mm-tall stick man, the creation from engineers at Rutgers University in New Jersey is made of 3D-printed hydrogels, which are more than 70% water. When electricity is applied to the prototype, its limbs change size and shape, propelling it through salty water.
As a soft and flexible robot, the device could lead to octopus-like creations capable of working underwater without damage, said mechanical engineer and senior author Howon Lee.
Traditional two-dimensional manufacturing techniques such as cutting, moulding and lithography have limited research possibilities with electroactive hydrogels (EAH), Lee told Professional Engineering. He said his team’s use of 3D printing, on the other hand, helped create multidirectional actuators capable of complex actions such as gripping objects.
The work could lead to “a deployable multifunctional device for inspection, disease diagnostics and drug detection/delivery,” Lee told PE.
“We believe that 3D printing of EAH with precise dimensional control could unlock otherwise untapped potential of EAH and may lead to various applications in soft robots, artificial muscles, and tissue engineering.”
Most other soft robot research involves devices with stretchy air chambers and inflation-based movement, Lee said.
He added: “They usually require tubing to supply the required air pressure and associated valves and control systems. Also, it is quite challenging to miniaturise these soft robots to micro-scale. Our 3D-printed hydrogel actuators are driven by material deformation, which is controlled by remotely applied electric field, allowing for untethered actuation.”
The team, which also involved an associate professor at Korea University in Seoul, is exploring “a few” practical applications, with underwater uses a particular interest. Further studies are needed to address issues including material strength, reliability and durability, Lee said.
A study was published in ACS Applied Materials & Interfaces.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.