----------- WHAT MIT Robotics Seminar Noah Jafferis, Harvard University "Insect-scale mechanisms: from flying robots to piezoelectric fans" WHERE 32-G449 (Kiva) WHEN Tuesday November 13, 11:00-12:00 Food will arrive right after the seminar ABSTRACT In recent years, there has been heightened interest in developing sub-gram hovering vehicles, in part for their predicted high maneuverability (based on the relative scaling of torques and inertias). In this regime, the efficiency of electromagnetic motors drops substantially, and piezoelectrics are generally the actuator of choice. These typically operate in an oscillatory mode, which is well matched with flapping wings. However, at such a small size, integrating on-board power and electronics is quite challenging (particularly given the high voltages required for piezoelectrics), and such vehicles have thus been limited to fly tethered to an off-board power supply and control system. In this talk, I will discuss recent advances in the Harvard Robobee to overcome these challenges, including non-linear resonance modeling, improved manufacturing, and multi-wing designs. I will also discuss fabrication of an alternative mechanism for converting piezoelectric vibration to airflow. This is of interest as a low-profile fan for CPU cooling, a growing issue as electronic devices pack increasing power consumption (and thus heat) into smaller spaces. Additionally, a thruster based on this technology could achieve higher thrust-per-area and speed than flapping wings or propellers (at the expense of efficiency). Its extremely modular nature is also attractive in such an application. When we operate robots near resonance, particularly with very non-linear systems and/or multiple mechanically interacting actuators, control can be extremely challenging. In these scenarios, knowledge of the instantaneous deflections or velocities of each actuator is crucial. Toward this end, I will describe our work on monitoring the actuatorsí current to obtain accurate velocity data regardless of external loading, without the need for any additional sensors. BIO Noah T. Jafferis obtained his PhD in the Electrical Engineering Department at Princeton University in 2012, and is currently a Postdoctoral Research Associate in Harvard University's Microrobotics Lab. Noah was home-schooled until entering Yale University at the age of 16, where he received his B.S. in Electrical Engineering in 2005. At Princeton, Noah's research included printing silicon from nanoparticle suspensions and the development of a "flying carpet" (traveling wave based propulsion of a thin plastic sheet). His current research at Harvard includes nonlinear resonance modeling, scaling, and system optimization for flapping-wing vehicles; piezoelectric actuators and motors (manufacturing and modeling for optimal power density, efficiency, and lifetime); a fan/thruster using piezoelectrically actuated peristaltic pumping; solar power for autonomous operation of insect-scale robots; and self-sensing actuation. Some of his many research interests include micro/nano-robotics, bio-inspired engineering, 3D integrated circuits, MEMS/NEMS, piezoelectrics, 3D printing, energy harvesting, and large-area/flexible electronics. _______________________________________________ Seminars mailing list Seminars@lists.csail.mit.edu https://lists.csail.mit.edu/mailman/listinfo/seminars