Clone Robotics is going to impressive lengths to make sure its "intelligent androids" will have some of the most human-like hands in the business, and watching the way their hydraulic "muscles" move under a transparent skin is absolutely hypnotic.
Do robots really need super-biomimetic hands? Probably not, in many applications; there are surely better task-specific designs out there for most jobs, and likewise there are surely other more generalized designs that can go far beyond the limitations of the human hand. On the other grippy claw, the urban world we live in is almost exclusively built around the bodies evolution has given us – particularly our hands. So there's definitely an argument for designs like Clone's.
Whatever your opinions on this topic, it's undeniably fascinating to watch the Clone hand moving, particularly since the team uses a transparent "skin" that lets you see a tangle of artificial muscles in action:
These muscles are the Clone team's own development on the idea of a McKibbin muscle. Effectively, these are mesh tubes with balloons inside them; such things have been around for decades. As the balloon expands, usually driven by either a pneumatic or hydraulic pump external to the muscle, its radial expansion forces the mesh to contract longitudinally.
Clone didn't want to use bulky external pumps; the team wanted a muscle you could simply apply an electric current to, and get it to contract in a reasonably controlled manner. So they came up with the idea of keeping the balloon filled with a fluid – at one point acetaldehyde – and running a powerful heating element through it. When a current is applied, the element quickly boils the fluid – in the case of acetaldehyde, taking it from atmospheric pressure at 20 °C (68 °F) to 6.6 times that pressure at 70 °C (158 °F).
You can see a version of this muscle being tested in the video below; it certainly contracts impressively quickly given how it works, but you can see the designers having to cool it with a water spray to get the thing to relax.
For a skeleton, Clone molded a set of relatively humanlike bones, with joints hinged to ensure a range of motion as close to the human hand as possible. The team claims some 27 degrees of freedom, the same as our own hands, with natural wrist movements and thumb rotations built in – all actuated, much like our own arms, by a complex tangle of muscles and tendons running the length of the forearm and through the hand itself.
It seems that on the current prototype, Clone has gone back to a simpler hydraulic system to drive the muscles, distributing pressure from a 500-watt, 145-psi water pump through a series of 36 electro-hydraulic valves, each with its own pressure sensor. There are also magnetic sensors to feed back information on joint angles and velocities to whatever brain is running it.
The company says it'll be shipping hand kits to customers by late 2022, although it's not yet nominated a price. The next product will be a full torso with a rigid spine, including 124 muscles through the neck, shoulders, arms, hands, chest and upper back. It'll ride on a "locomotion platform" that carries its battery pack. But the focus will be on these hands, and rightly so. Check out the team's latest video below.
Source: Clone Robotics