Why Robots That Bend Are Better

Soft robots are built from flexible materials like plastic tubing instead of metal or wood.

Zach Hammond at Stanford demonstrated a soft robot that uses punctuated rolling locomotion, tipping over faces to move forward.

A turtle-inspired soft robot made of flexible tubing, powered entirely by compressed air with no electronics required.

Can be used in hazardous environments like mines where electronics could spark explosions or near MRI machines with strong magnetic fields.

• Soft robots are safer for operation around humans due to their compliant structure • They have a maximum force limit they can exert, making them inherently safe • Can withstand being beaten, stood on, and compressed without danger

Main structural members are fabric tubes (nylon) inflated with air, with polyethylene tubes inside for air tightness.

Tubes are inflated to about six PSI above atmospheric pressure, roughly 1.5 atmospheres total.

Each tube passes through pairs of rollers connected to a motor that pinches the tube like a pinched straw, with high friction material preventing slippage.

• Built by Zach Hammond and one other grad student in about one month • All structural members were hand-sewn by the team

Made of four inflated tubes connected to pairs of motors forming triangular sides, creating an octahedral shape overall.

Robots are named after sausages based on their appearance, including Polish, Chorizo, Linguica, and Kielbasa.

• Can dramatically change shape from tall to short and squat • Overall perimeter remains constant, making it isoparametric • Controlled via MATLAB GUI where operators input desired positions in inches

Hard robots are strong and precise with accurate and repeatable actions, but are heavy and cannot change volume drastically.

• Can become tall to go over obstacles or short to fit under obstructions • Tubes bend around disturbances and rocks without damage • Still capable of carrying heavy loads

Soft robots are designed to convince people that robots are good, soft, kind, and friendly, contrasting with the terrifying appearance of Boston Dynamics robots.

Can shrink down their volume drastically, which is valuable for space applications where volume is an expensive premium for rocket transport.

• NASA explored soft robots for space missions • Potential deployment under ice sheets by drilling through and inserting robots through small diameter holes • Can be disassembled and reassembled to form larger structures in difficult-to-access areas

Inspired by octopuses, these robots use shape-changing ability and compliance to squeeze through tight passageways and wrap around objects for manipulation.

Due to tube compliance, the robot naturally grasps and manipulates objects as tubes bend slightly, increasing contact area and distributing forces evenly.

• Biggest risk is punctures or leaks since compressed air is essential for structure • Mitigation strategies include onboard small compressors to maintain pressure during minor leaks • Future will see more soft robots as they work closer with humans