Engineers have been developing insect-like microbots capable of flight for any number of applications, including Harvard’s RoboBees (could pollinate crops), and the University of Wahington’s RoboFly (may detect pollutants/contaminants). These microbots have one thing in common — they utilize moving parts (wings) to achieve flight, which is difficult and complicated when you factor in the amount of DOF needed to travel in any direction.
Researchers from UC Berkeley are designing a mini microbot that eschews those moving parts but is still capable of taking flight. Their Ionocraft doesn’t follow the same biomimetic approach as the others but instead relies on electrohydrodynamic thrust to provide lift, which is a technique to create air-flow using electrical energy.
Measuring just 2cm x 2cm and weighing 30mg, the Ionocraft uses ‘ion-thrusters’ that take advantage of a high-strength electrical field to generate ionized air. Ions within that air are drawn to a negative-charged grid, and while on their way to that grid, they collide with neutral air molecules, giving them momentum and thus trust. The microbot uses four thrusters, which were designed using a thin emitter wire and a collector grid. When a voltage is applied between the two it produces a positive ion cloud, which is drawn to the negative grid, air is pushed and boom, thrust. Flight control is done using an onboard IMU, and by altering the amount of current for each thruster, allowing it to move similarly to quad-copters- controlling direction, roll, pitch, and yaw.
As it stands at this point, the Ionocraft is powered via tether using 2,000v at slightly under 3.5mA and doesn’t carry anything other than the IMU. The researchers are continuing development of the Ionocraft and hope to increase its payload to include a control ASIC, driver circuit, optical flow sensor, and onboard solar panels to give it untethered, autonomous flight capabilities.