OrcaHand

OrcaHand is the open-source tendon hand from the Soft Robotics Lab at ETH Zurich led by Robert Katzschmann, published in April 2025 and presented at IROS 2025. Seventeen servos form a motor tower in the forearm: sixteen pull the tendons of five fingers and the seventeenth turns the wrist through a belt. Buyers choose between Dynamixel units, sixteen at 0.92 Nm plus one at 1.9 Nm, or seventeen Feetech STS3215.

The hand weighs about 1.2 kg; the paper demonstrates a 10.5 kg, or 103 N, four-finger payload and 2 kg, or 19.6 N, on the index finger alone at 600 mA. Force-sensing resistors sit on all five fingertips and motor current is monitored, although tactile sensing is optional on the commercial kit.

The orca_core firmware provides position control with automatic calibration and a tendon tensioner, the hand survived 10,000 cycles without failure, and it mounts on an ISO 9409-1 flange. Software is MIT-licensed, hardware under a Creative Commons licence for non-commercial use. According to ROBOTIS America in October 2026 the Dynamixel kit costs USD 4,500, while self-built parts stay under CHF 2,000.

The OrcaHand Touch adds a tactile skin and the OrcaHand Lite trims the design; the commercial mimic hand M1 from the same city is not sold separately.