Robotic Venus flytrap snaps at flashing ‘bugs’
Hungry plant inspires creators of ‘gripper’
Researchers designing agile robots generally look to agile animals, such as cockroaches and sharks, for ideas. Now a fast-moving robot has been created from an unlikely source of inspiration: a plant.
The plant is the carnivorous Venus flytrap, which catches its own dinner. Like the real flytrap, the synthetic flytrap can snatch objects flitting through the air and hold them tight between its “jaws.” And like the real thing, the laboratory version can discriminate between different kinds of “prey.”
“Of course, the Venus flytrap is smarter and more advanced in all ways” than the new device, says Arri Priimägi of Finland’s Tampere University of Technology, a member of the team that built the artificial flytrap. Still, he says, his team’s creation “can grip objects. We can move them in a very controlled manner from one place to another, and the weight of the object can be hundreds of times higher” than the weight of the robot.
The Finnish flytrap has a “gripper” made of a rubbery material sensitive to light. A slender cable on the gripper transmits light.
A bright object — a grain of sugar, say, or a scrap of foil — reflects this light as a mirror would. When enough reflected light hits the gripper, its ends bend up into a U shape, capturing the object. An object that doesn’t reflect much light is allowed to fly on by.
The gripper can close in a fifth of a second, roughly half as fast as the Venus flytraps lobes clamp onto a fly, the team reported in this week’s Nature Communications.
Priimägi calls the device a “breakthrough” because it’s spurred to action by light signals from its surroundings, which could be “a step toward intelligent micro-robotics.”