BioflexBot: A Spring-and-Air Robot Hand That Out-Rotates Human Fingers

Key points

• The BioflexBot gripper, published in the journal Advanced Science in 2025, uses a coiled spring and compressed air rather than finger-shaped mechanics.
• It can rotate roughly four times further than a human wrist and grasp objects up to 13 times larger than comparable robotic grippers.
• The team demonstrated it inspecting aeroplane engine blades, assisting a humanoid robot with household tasks, and running a chemistry experiment.
• Two senior authors from Chinese universities say the design cuts both hardware cost and control complexity compared with human-shaped robotic hands.

Most robotic hands fail for the same reason: they copy the shape of a human hand. Bones, tendons, joints, all recreated in metal and silicone. The result is a mechanism that is expensive to build and genuinely difficult to control.

Researchers at institutions including the Chinese University of Hong Kong, Shenzhen and the Nanjing University of Information Science and Technology tried a different question. Forget the shape. What are the core things a hand actually does?

The answer they settled on: pinch small objects, rotate things, hook onto handles, and grasp items of very different sizes. Four functions. Their prototype, called the BioflexBot, delivers all four using a coiled spring, a constraining shell (a casing that channels how the spring bends), and a pneumatic system, meaning a system that uses compressed air to move mechanical parts, with just two air inputs.

What can it actually do?

In short: more than a human hand in some directions, and at a fraction of the usual cost. The researchers published their validation tests in the peer-reviewed journal Advanced Science, which is published by Wiley.

For delicate work, the gripper picked up an acupuncture needle and transferred liquid using a laboratory pipette without spilling. Those are fine-motor tasks that trip up most industrial robots.

For rotation, it turned a bottle cap nearly four times further than the human wrist can manage. For reach, the device extends and contracts 3.5 times more than a human hand, which matters when you need to deliver something into a tight space or grab several objects in a row without resetting.

Grasping range was perhaps the most striking figure: the BioflexBot handled objects up to almost 13 times larger than what comparable gripper systems can manage.

Does this have real-world uses?

Yes, the team showed three. A camera attached to the gripper inspected the blades inside a 3D-printed model of an aeroplane engine, reaching curved surfaces that a rigid tool could not follow. A second demonstration paired the BioflexBot with a full humanoid robot body for everyday tasks. A third ran a basic chemistry experiment.

First reported by The Robot Report, the researchers describe their aim plainly. "Unlike most robotic hands that replicate the human form, at high hardware and control costs, our approach focuses solely on mimicking the functions, not the shape," said senior author Yang Yang.

The team says the next step is moving from a laboratory prototype to a fully automated platform. No timeline was given.

What does this mean for patients and workers?

For now, this is research, not a product on sale. But the direction matters. A gripper that handles both a needle and a heavy toolbox with the same two-air-input system could eventually assist in operating theatres, pharmacies, or care settings where tasks swing between delicate and forceful many times a day. Cheaper, simpler control also means smaller clinics and labs could realistically afford the hardware.

Watch for peer replication and larger trials before reading too much into early demonstrations.