Generally speaking, robotic "hands" vary between rigid devices with a firm grasp, and softer, gentler gadgets that are a bit wimpier. Now, however, scientists have created an appendage that they claim combines the best features of both.
When it comes to picking up heavy, sturdy objects, robots typically utilize two-fingered grippers. With their rigid design, these don't have a particularly gentle touch, but they can exert a lot of force. Softer-bodied, more compliant hands are used for lifting fragile items. These are less likely to break things, but they also don't have a particularly firm grip.
Led by Changyong Cao, researchers at Michigan State University set out to bridge the gap between the two.
The resulting prototype has four fingers and an opposable thumb, each one incorporating what is known as a flexible hybrid pneumatic actuator, or FHPA. At the core of each FHPA is a "bone-like" leaf spring, which is surrounded on the outside by softer actuated air bladders.
As air is pumped in and out of those bladders, each finger opens and closes independently of the others. And because the outsides of the fingers are relatively squishy, they conform to the contours of fragile objects, keeping those items intact. At the same time, though, the leaf springs deliver more grasping force than would be possible with a completely soft-bodied device.
It is hoped that once the technology is developed further, FHPA-enabled hands could be utilized in applications such as fruit-picking operations, medical care, and surgical procedures.
The research is described in a paper that was recently published in the journal Soft Robotics.
Source: Michigan State University
