"High Aspect Ratio Microactuators and Instrumented
Steel Suspensions for Vibration Suppression in Computer
Hard Disk Drives"
Kenn Oldham
Ph.D. Candidate
Computer Mechanics Laboratory
University of California at Berkeley
Abstract
As the data density in hard disk drives
increases, airflow-induced vibration of the disk drive servo
assembly becomes a major obstacle to achieving sufficient
data tracking accuracy with the read-write head. Microdevices
contributing additional actuation and sensing capabilities
to the servo assembly may help suppress these structural
vibrations. First, a MEMS microactuator operating in a dual-stage
actuation scheme provides fine-positioning of the read-write
head, beyond the capability of a traditional voice-coil
motor operating alone. Robust, high-force silicon microactuators
have been successfully flown and controlled in a disk drive.
Second, miniature strain gages added to the flexible metal
suspension of the disk drive servo arm provide high-rate
measurements of suspension vibration. A novel closed-loop
optimization scheme is used to identify ideal locations
and geometries of the strain gages, while microfabrication
techniques adapted to stainless steel substrates produce
high-resolution strain sensors in a compact area. Robust,
multi-rate controllers have been developed for operation
of the dual-stage, instrumented system.
BIO: Kenn Oldham is a
doctoral candidate in mechanical engineering at the University
of California at Berkeley. Research interests include micro-mechatronic
systems, robust control design, novel microfabrication techniques,
and sensor and actuator design. Mr. Oldham's dissertation
research explores the design, fabrication, and control of
MEMS microdevices in computer hard disk drives. He holds
a bachelor of science degree in mechanical engineering from
Carnegie Mellon University, and will complete his doctoral
degree from Berkeley in June 2006. He is currently an ADEPT
Fellow in the University of California at Berkeley School
of Engineering.
Monday March 13, 2006
11:30am
337 Towne
