Design and Fabrication of Ultralight High-Voltage Power Circuits for Flapping-Wing Robotic Insects


Flapping-wing robotic insects are small, highly maneuverable flying robots inspired by biological
insects and useful for a wide range of tasks, including exploration, environmental monitoring, search
and rescue, and surveillance. Recently, robotic insects driven by piezoelectric actuators have achieved
the important goal of taking off with external power; however, fully autonomous operation requires
an ultralight power supply capable of generating high-voltage drive signals from low-voltage energy
sources. This paper describes high-voltage switching circuit topologies and control methods suitable
for driving piezoelectric actuators in flapping-wing robotic insects and discusses the physical
implementation of these topologies, including the fabrication of custom magnetic components by
laser micromachining and other weight minimization echniques. The performance of laser
micromachined magnetics and custom-wound commercial magnetics is compared through the
experimental realization of a tapped inductor boost converter capable of stepping up a 3.7V Li-poly
cell input to 200V. The potential of laser micromachined magnetics is further shown by
implementing a similar converter weighing 20mg (not including control functionality) and capable of
up to 70mW output at 200V and up to 100mW at 100V.


[1] R. J. Wood, “Liftoff of a 60mg flapping-wing
MAV,” in IEEE/RSJ Int.Conf. on Intelligent
Robots and Systems, 2007, pp. 1889–1894.
[2] E. Steltz, M. Seeman, S. Avadhanula, and R. S.
Fearing, “Powerelectronics design choice for
piezoelectric microrobots,” in IEEE/RSJ Int.
Conf. on Intelligent Robots and Systems, 2006,
pp. 1322–1328.
[3] D. Campolo, M. Sitti, and R. S. Fearing,
“Efficient charge recovery method for driving
piezoelectric actuators with quasi-square
waves,” IEEE Trans. Ultrasonics,
Ferroelectrics, and Frequency Control, vol. 50,
no. 3, pp. 237–244, March 2003.
[4] A. Wilhelm, B. W. Surgenor, and J. G. Pharoah,
“Evaluation of a micro fuel cell as applied to a
mobile robot,” in IEEE Int. Conf. on
Mechatronics and Automation, 2005, pp. 32–
[5] M. Karpelson, G.-Y. Wei, and R. J. Wood,
“Milligram-scale high-voltage power
electronics for piezoelectric microrobots,” in
IEEE Int. Conf. on Robotics and Automation,
2009, pp. 883–890.
[6] R. J. Wood, E. Steltz, and R. S. Fearing,
“Optimal energy density piezoelectric bending
actuators,” Sensors & Actuators: A. Physical,
vol.119, no. 2, pp. 476–488, 2005.