Researchers have designed a small, flying robot that can perch on a wide range of surfaces before taking flight once more. The development is highlighted in the 20 May issue of Science.
Aerial robots can serve many valuable purposes, such as surveying a site after a natural disaster or detecting hazardous chemicals — but the act of flight is energy-intensive. For animals that fly, such as birds and insects, a key way to conserve energy is to find a place to perch.
"Unfortunately, today's flying microrobots run out of energy quickly," explained Moritz Alexander Graule of the Massachusetts Institute of Technology. "We want to keep them aloft longer without draining too much energy. For our robot, the perching method we developed requires about 1,000 times less energy than flying, thus prolonging the potential mission time."
While there are a number of different options for creating a perching robot, not all translate well for small-scale robots. For example, applying a chemical adhesive to help a robot attach to a surface may facilitate an initial landing, but can be problematic when the lightweight robot needs to detach from its perch and resume flight.
Instead, Graule and colleagues created a bio-inspired robot that perches using an electrostatic landing patch. The patch evenly distributes a static electric charge, which is attracted to the charge of the surface where it can land, causing the robot to cling to the surface. When the charge created in the patch switches off, the robot can relaunch itself. The patch is made of foam to help dampen the impact of landing, so that the robot does not bounce off of its perching target.
Study co-author Rob Wood of Harvard University said, "Beyond the manufacturing challenges, flight control is difficult in particular when attempting to alight to a target surface."
For optimal landing, the adhesive patch must be aligned perfectly with its target. To address this, the team turned to a visual technique that honeybees use to land, developing a system of motion-tracking cameras to help the robot zero in on its target.
Through a series of videos, the team demonstrated the robot's ability to perch on a variety of surfaces — including glass, wood, and even a natural leaf — before resuming flight.
Wood said, "This is a platform we have been developing for more than ten years and there is still a number of remaining challenges that need to be solved before these robots are useful for tasks [such as search and rescue, and hazardous environment exploration]."
Now, his team is currently designing custom circuits for on-board control and developing on-board power sources for these miniature robots, which could one day take over dangerous tasks that currently put human life at risk.
[Credit for associated teaser image: Aerial Robotics Laboratory/ Imperial College London]