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Upcoming event by the IEEE Wash/ NoVA Sensor Council Chapter:

Date and Time: Wed, Oct. 15, 12pm (noon)-1pm (Pizza lunch will be provided)

Place:   Ballston Conference Center, 3811 North Fairfax Drive, Suite 600, R#602,  Arlington, VA 22203 (please sign in at the reception)

Contact: Jurgen Daniel (jhdaniel@ieee.org), 408-515-0045

 

Title: THIN FILM PZT PIEZO MEMS FOR MICRO-ROBOTIC ANGULAR RATE SENSING AND ROTARY ACTUATION

Speaker: Gabriel L. Smith, US Army Research Laboratory, Adelphi, MD

Abstract:

This talk will focus on advancements in integrated PZT MEMS (micro-electromechanical system) based angular rate sensors and ultrasonic travelling wave motors for use in mm-scale robotic applications. Ongoing research at the Army Research Laboratory in radio frequency (RF) devices and mm-scale robotics has lead to progress in Lead Zirconate Titanate (PZT) actuation and sensing performance.1 High displacement unimorph actuators have demonstrated two axis resonant kinematics of drosophila (fruit fly) wings2. Robotics, at this scale, creates a need for integrated PZT-based rate sensors for stable flight.   Dipterian insects use two club like vibrating structures (haltere) to measure three-axis angular rate. A unique ARL process and sensor design integrates PZT and high aspect ratio copper structures making a haltere that can drive and sense in two orthogonal directions. This bio-inspired approach has potential to yield three axis sensor elements at 3 orders of magnitude less in volume than the packaged state of the art rate gyros. Piezoelectric travelling wave ultrasonic motors (TWUM) offer the advantages including low profile, high torque/volume ratios, and high efficiency. TWUM have been commercialized at the cm and larger scale, 3,4 but wafer level batch fabricated mm-scale and smaller motors have been elusive due to tolerance limits affecting travelling waves. ARL has modelled, fabricated, and demonstrated controllable travelling waves and reversible 0-2300 RPM motor operation on a 3 mm rotor with a 2mm stator. The PiezoMEMS TWUM approach will enable integration of arrays of TWUMs at the wafer level to commercial, defense, and medical applications including mm-scale robotic platforms for locomotion, servos for control of larger robots, and sensor orientation.

  1. Smith, G. et.al, “PZT-Based Piezoelectric MEMS Technology” Journal of the American Ceramics Society 95 [6] 1777-1792 (2012).
  2. J. S. Pulskamp, et. al, “Two Degree of Freedom PZT MEMS Actuated Flapping Wings With Integrated Force Sensing,” Proc. Solid State Sensor, Actuator and Microsystems Workshop, Hilton Head Island, South Carolina, 390-391, (2010).
  3. V. Kaajakari, et. al, Micromachined ultrasonic motor based on parametric polycrystalline silicon plate excitation, Sensors and Actuators A: Physical 137 (June) (1) (2007) 120–128.
  4. K. Uchino, Piezoelectric ultrasonic motors: overview, Smart Material Structures 7 (1998) 273–285.

Bio:

Gabriel L. Smith received B.S. and M.S. degrees in mechanical engineering from the University of Maryland, College Park, in 1999 and 2002, respectively. He has worked in MEMS Design for the past 17 years with the U.S. Naval Surface Warfare Systems, U.S. Army Armaments Research Development Engineering Center, and U.S. Army Research Laboratory. He has worked on MEMS devices for safe and arm devices for torpedoes and gun-launched munitions, impact switches for target and launch detection, Piezo sensors and actuators for mm-scale robotic systems, and Piezo traveling wave ultrasonic motors. He currently holds 8 eight US patents with 3 three patents pending and has authored 9 nine journal and conference papers on MEMS devices.