In recent years, scientists and engineers have looked to muscles as potential actuators for “biohybrid” robots that could squirm and wiggle through spaces where traditional machines cannot. For the most part, however, researchers have only been able to fabricate artificial muscle that pulls in one direction, limiting any robot’s range of motion. MIT engineers recently developed a method to grow artificial muscle tissue that twitches and flexes in multiple coordinated directions. 

MIT researchers fabricated an artificial iris using a new “stamping” approach they developed. First, they 3D-printed a small, handheld stamp patterned with microscopic grooves, each as small as a single cell. Then they pressed the stamp into a soft hydrogel and seeded the resulting grooves with real muscle cells. The cells grew along these grooves within the hydrogel, forming fibers. When the researchers stimulated the fibers, the muscle contracted in multiple directions, following the fibers’ orientation. “With the iris design, we believe we have demonstrated the first skeletal muscle-powered robot that generates force in more than one direction,” said Ritu Raman, the Eugene Bell Career Development Professor of Tissue Engineering in MIT’s Department of Mechanical Engineering.

Get all the details in this fascinating article written by Jennifer Chu for MIT News. You can find the entire piece here. 

*Image courtesy of the researchers.