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A chiral object has a mirror image that cannot be superimposed on itself. A common example is the human hand. The left is a reflection of the right, but the two cannot be placed on top of each other or rotated in a way that would make their shapes appear identical.

The researchers used 3D printing to create a device that mimicked the passion fruit’s dehydration process. They created hemisphere-shaped moulds with a hexagonal pattern on the surface, which they filled with liquid silicone to make a ball. The ball has a small hole that serves as an air channel connecting an internal cavity and an external tube for air extraction.

When air is pumped out, the soft silicone ball shrinks like a dried passion fruit, tightly grasping any item next to it and locking it in place. When the device’s cavity is inflated, it releases the object.

The team tested the device with a diamond, the hardest known material, grabbing it from multiple angles. They also used the device to grab other small objects, including nuts, screws, mung beans, soybeans, blueberries, heart-shaped candy, glass fragments and a glass ball.

Xu said the team would develop similar devices in other shapes, such as a human hand or animal paw, to recreate the precise grasping ability of fingers.

According to Xu, smart materials such as magnetic powder and liquid crystal could be used in future devices, allowing them to morph into different shapes.