Materials

Powerful, Flexible 'Tension' Piston: 300-Year Old Design Reinvented

Invented in the 1700s, pistons harness the power of fluids to perform work in many machines and devices. Traditional pistons are made of a rigid chamber and a piston inside, which can slide along the chamber’s inner wall while maintaining a tight seal. The high friction between the moving piston and the chamber wall can cause the seal to breakdown, which leads to leakage. Roboticists from Harvard University and MIT have developed a new way to design pistons that replaces the rigid elements with a mechanism that uses compressible structures inside a membrane made of soft materials. The resulting “tension pistons” generate over three times the force of traditional pistons, eliminate a lot of friction, and are up to 40% more energy efficient.