Harvard RoboBee / RoboBee X-Wing

Overview

The smallest flying robot of its era. It made its first controlled flight in 2012 and was published in Science in May 2013, made possible by pop-up MEMS folding fabrication and piezoelectric wing actuators. Later variants perched with electrostatic adhesion and switched between swimming and flying. The four-winged RoboBee X-Wing (2019) became the lightest vehicle to achieve sustained untethered flight, powered by solar cells under lab lights.

In April 2025 the team added long, jointed legs modeled on the crane fly, published on the cover of Science Robotics. A new controller slows the robot near the ground, so it lands gently and the fragile piezoelectric actuators are protected. This version weighs about 0.1 g, has a 3 cm wingspan and still flies on a tether to off-board control. The next goal is a larger RoboBee with onboard sensors, power and control.