Untethered soft robots mechanically adapt to their surroundings and tasks and are becoming more agile and controlled.
Cornell University researchers led by Kirstin Petersen, assistant professor of electrical and computer engineering, designed a new system of fluid-driven actuators allowing soft robots to achieve more complex motions. They published their findings as “Harnessing Nonuniform Pressure Distributions in Soft Robotic Actuators” in Advanced Intelligent Systems.
The goal was to take a robot’s cognitive capabilities and behaviors and offload them from the “brain” onto the body via mechanical reflexes allowing for a simpler, more robust, and less expensive robot for manufacturers.
The team connected a series of elastomer bellows with slender tubes that allowed for antagonistic motions (pulls and one that pushes). The tiny tubes induce viscosity, which distributes the pressure unevenly, bending the actuator into different contortions and motion patterns. Researchers developed a full descriptive model that could predict the actuator’s possible motions with a single fluid input. That results in an actuator that achieves far more complex movements without multiple inputs and complex feedback control.
The soft robot built has six legs, two syringe pumps on top, walks at 0.05 body lengths per second, and crouches. It could have applications such as robot arms and, with modifications, other apps.