Inspired by the biology of a fly, with submillimetre-scale anatomy and two wafer-thin wings that flap almost invisibly, 120 times per second, Harvard’s tiny RoboBee has taken its first controlled flight. Catch RoboBee in action in the video above…
The demonstration of the first controlled flight of an insect-sized robot is the culmination of more than a decade’s work, led by researchers at the Harvard School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering at Harvard.
Half the size of a paperclip and weighing less than a tenth of a gram, the tiny device not only represents the absolute cutting edge of micromanufacturing and control systems; it is an aspiration that has impelled innovation in these fields by dozens of researchers across Harvard for years.
The tiny robot flaps its wings with piezoelectric actuators – strips of ceramic that expand and contract when an electric field is applied. Thin hinges of plastic embedded within the carbon fibre body frame serve as joints, and a delicately balanced control system commands the rotational motions in the flapping-wing robot, with each wing controlled independently in real-time.
At tiny scales, small changes in airflow can have an outsized effect on flight dynamics, and the control system has to react that much faster to remain stable.
The robotic insects also take advantage of an ingenious pop-up manufacturing technique that was developed by RoboBee principal investigator Robert J Wood’s team in 2011. Sheets of various laser-cut materials are layered and sandwiched together into a thin, flat plate that folds up like a child’s pop-up book into the complete electromechanical structure.
The quick, step-by-step process replaces what used to be a painstaking manual art and allows Wood’s team to use more robust materials in new combinations, while improving the overall precision of each device.
“We can now very rapidly build reliable prototypes, which allows us to be more aggressive in how we test them,” says co-lead author Kevin Y Ma, adding that the team has gone through 20 prototypes in just the past six months.
Applications of the RoboBee project could include distributed environmental monitoring, search-and-rescue operations, or assistance with crop pollination, but the materials, fabrication techniques and components that emerge along the way might prove to be even more significant. For example, the pop-up manufacturing process could enable a new class of complex medical devices.
“Now that we’ve got this unique platform, there are dozens of tests that we’re starting to do, including more aggressive control manoeuvres and landing,” says Wood, the Charles River Professor of Engineering and Applied Sciences at SEAS and a Wyss Core Faculty Member.
After that, the next steps will involve integrating the parallel work of many different research teams who are working on the brain, the colony co-ordination behaviour, the power source, and so on, until the robotic insects are fully autonomous and wireless.