20, 1998 Design News
Useful technology for your
Metallic layers, adhered to each side of the
pre-stressed piezoceramic element, protect it
from potential damage. The composite design
withstands higher voltages, and results in increased
force and displacement.
Based on patented technology licensed from NASA, THUNDERTM
solid-state actuators and sensors use a pre-stressed
piezoceramic element bonded between metallic layers
with a polyamide adhesive. The composite structure with
characteristic curvature allows the piezoceramic element
to withstand higher voltages.
The low-cost, high-displacement actuator or sensor
design is robust, reliable, and offers low power consumption
and efficient energy conversion. Devices come in a wide
variety of shapes and sizes--disks, squares, and strips--from
a few millimeters to many centimeters in size.
Various mounting and multiplexed configurations, such
as nested or clamshell stacks, offer flexibility to
customize displacement or force to specific applications
such as motors, pumps, or valves.
Norvell Rose, Face Intl. Corp.
427 West 35th St.
Norfolk, VA 23508
Pre-stressed Bellville spring disengages safety
coupling within 4 msec to prevent costly machine
and drive damage on high-production transfer
To prevent costly machine and drive damage on high-production
transfer lines, direct-drive and indirect torque-limiting
safety couplings disengage highly dynamic drives within
2 to 4 msec of the overload signal, then automatically
re-engage at the precise angular position.
A pre-stressed Bellville spring generates fast switching
times, and protects equipment from even ultra-short
speed surges. Internal precision roll or ball guides
guarantee backlash-free torque transmission in both
rotational directions and under high accelerations.
Frank Jin, Rimtec Corp.
825 N. Cass Ave., Suite 305
Westmont, IL 60559
Using the same materials as computer chips?silicon,
silicon dioxide, and silicon nitride?this
new electrostatic chuck design should result
in lower manufacturing costs and fewer batch
Electrostatic chucks support and help cool silicon
wafers during manufacturing. Conventional types use
expensive, dielectric materials in the chuck's face
that can introduce contaminants. Moreover, mechanical
damage may result if the static-holding charge takes
too long to discharge, as is often the case.
To lower costs, decrease cycle time, and generate less
scrap, a new chuck face made of an easily produced,
patterned silicon wafer, uses tiny, non-conductive silicon
dioxide islands on its surface. These micromachined,
non-conductive raised areas on the chuck face prevent
excessive currents when the strong electric field is
applied between the chuck face and the clamped wafer.
Result: fast on/off cycling for quicker de-chucking.
Carl Seager, Sandia National Laboratories
Albuquerque, NM 87185
Class 100 clean-room compatible servo wheel
uses a planetary gear and motor drive built
into the wheel?s hub to deliver high torque
in a compact package.
Clean-room compatible (to class 100) servo wheel uses
a complete gearmotor system built into its hub to power
small electric vehicles such as automatic guided vehicles,
material handling equipment, industrial floor-cleaning
equipment, and robots.
The sealed unit has no internal sparking. Reliable
in explosive, hostile, or wet environments, the package
provides high radial shock load capacity and has no
brushes to wear out or replace.
Planetary gear reduction delivers high torque capacity
in a compact design that is lubricated for the system's
life to reduce maintenance. Low electromagnetic interference
eliminates the need for heavy shielding, and built-in
position sensing eliminates the need for an encoder
John Deverdits, Rockland Servo Wheels
27 Seaview Blvd.
Port Washington, NY 11050
(516) 484-5482 x140