Robotics

ARTiS Jams a Soft Palm Around Screwdrivers, Drills, and Hammers

Shar Hendrix 4 min read

Holding a tool while you use it is a different problem from picking a block. Roman Mykhailyshyn, Yukiyasu Domae, and Kensuke Harada (AIST Embodied AI and the University of Osaka) posted ARTiS on 3 September, an adaptive gripper aimed at assembly and disassembly. The paper is accepted at IEEE Transactions on Automation Science and Engineering.

The trick is a jamming palm plus Fin-Ray fingertips. The palm is a latex membrane; at 400 kPa supply pressure it reaches vacuum in 0.7 s. Fingers use Dynamixel MX-64R (6 N·m limit) and MX-28R (2.5 N·m). One finger has 2 DoF, the other two have 3 DoF, 7 in total. Two fingers can swing 0–70° around the gripper axis; each fingertip yaws ±90°.

Human hand holding a screwdriver next to the ARTiS gripper with a jamming palm and adaptive fingertips
Human grasp versus ARTiS on a screwdriver. Source: Mykhailyshyn et al. / ARTiS project page.

Two tips, then the tools

Tip 1 is a power-sphere: four TPU-95A Fin-Ray petals on a rigid holder, tied with a rubber ring. Tip 2 is a power-wrap: opposing small Fin-Rays under a 0.3 mm ellipse. Robustness tests press objects at 0–50° and repeat 30 times.

The tool set is ordinary shop junk: nine screwdrivers (0.056–0.148 kg), two drills (0.284 kg and 1.040 kg), two hammers (0.230 kg and 0.742 kg). Precise grasp: open fingers, mash the palm onto the handle, suck air, lift, close Tip 1 on the shaft. Power grasp uses Tip 2 on the table instead of a holder.

They bolt ARTiS to a UR-5e at 45° to the bench. Scoring is not just “did it lift.” The sequence is grasp, reorient or use, then put the tool back. Some handles fail: cheap smooth ABS on screwdriver #3 and #8, and the bulky Drill #1.

CAD cutaway of ARTiS showing jamming cavity, Dynamixel motors, and Fin-Ray tips
CAD: jamming cavity, MX-64R/MX-28R, Tip 1 and Tip 2. Source: ARTiS project page.
Grid of ARTiS holding screwdrivers, a drill, and hammers in sphere and wrap grasps
Sphere and wrap holds across the study tools. Source: ARTiS project page.

Collaboration, not just pick-and-place

A collaborative sequence has the gripper pin a part so a person can unscrew it: palm down, finger pose, jam, clamp. Other stills show wedging a screwdriver into a car air-conditioner joint, driving a nail, and YCB objects for a generalization check. Hardware tutorial, purchase list, CAD, and code are on the project site. Support listed: NEDO Exploratory Research and Denso Robotics.

Air use stays under 20 L/min, which the authors say a lab compressor can feed. They did not measure how much faster the palm sets above 400 kPa.

A Human’s Take

A gripper that is allowed to look like a hand and a suction bag is the right answer for a screwdriver you still have to hit with a hammer. I care that they scored reorient-and-return, not a lift-and-smile. If the CAD is actually buildable from the purchase list, this is a weekend project for a UR cell. If Drill #1 still slips, that is the receipt, not a footnote.

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