Soft Robotics with Hydrogels

Robotics continue to evolve.  Smaller, softer.   More specifically dedicated. 

Hydrogels pave the way for the future of soft robotics

by Giordana Verrengia, Carnegie Mellon University Mechanical Engineering

Researchers in Carnegie Mellon University's College of Engineering have created an open-source, commercially available fiber extruder to benefit future research with hydrogels and soft robotics.

As their name suggests, hydrogels begin in liquid form as monomers. This viscous liquid, which can be made of synthetic or natural materials from polyester to sodium alginate, can be used as ink for 3D printing. The ink is first loaded into a syringe, then pumped through the needle as a thin filament and solidified following 3D printing to form a multidimensional structure, in the same way that Jell-O is mixed up first as a liquid before turning into a soft, bendable dessert. When hydrogels are placed in the right environment, the monomers in the liquid crosslink to form polymers, which gives shape to the hydrogel and lets it trap water.

You might imagine that these supple materials are also delicate—and that's one drawback of working with hydrogels for robotic applications. To solve this problem and allow hydrogels to be used in a greater variety of tasks and harsh environments, Wenhuan Sun, a Ph.D. student in mechanical engineering, co-advised by Victoria Webster-Wood and Adam Feinberg, designed a continuous fiber extruder, a device that reinforces the hydrogels, so they don't easily break apart or lose their shape when loaded. Feinberg, a professor of biomedical engineering and materials science and engineering, previously created the 3D printer that the fiber extruders were first tested on .... '