US Army soft robots can squeeze into tight spaces

Engineers at the U.S. Army research laboratory’s Institute for Soldier Nanotechnologies (ISN) at MIT have developed a 3D printing platform that can enable both the modelling and design of complex magnetically actuated devices. The technology is earmarked for producing soft robots that can crawl, roll, jump, or grab, fulfilling tasks such as squinting into cracks in the wall of a cave, jump over a trip wire, or crawl under a vehicle: all tasks which soldiers cannot perform safely.

The technique uses an elastomeric composite as ink, infused with ferromagnetic microparticles. This material is printed through a nozzle to which a magnetic field is applied. This re-orients the magnetic particles along the field, imparting a patterned magnetic polarity to the filaments that are printed.

Using this, the researchers can programme ferromagnetic domains into complex 3D-printed soft materials to enable “previously inaccessible modes of transformation”. The mechanical actuators formed by these domains are orders of magnitude faster and have much greater power density than existing 3D-printed active materials, the team claims.