Imagine a drill that penetrates granite using only the power of a flashlight
battery. Then imagine sending that energy-efficient drill to another planet
to explore beneath the surface. Or, perhaps, visualize putting the
lightweight, sensitive instrument to work on Earth to improve medical care.
Such a drill, recently developed at JPL and Cybersonics, Inc., has that
power and potential.
The Ultrasonic/sonic driller/corer demonstration unit weighs roughly .7
kilograms (1.5 pounds) and is able to drill 12-millimeter (half-inch) holes
into hard rocks. Attached to the robotic arm of a future lander or on board
a small rover, the drill could extract samples from the surface of an
asteroid or planet surface during space missions. On Earth, potential
medical uses include extracting pacemaker leads, assisting surgeries or
facilitating diagnostic procedures that involve drilling into bone.
The drill relies on a novel mechanism that produces high frequency
vibrations and converts them to a hammering action at low frequency. The
high frequency vibrations are generated by a stack of piezoelectric wafers,
which can be powered by a battery. The drill consists of only three moving
parts and it does not require gears, motors or lubricants. The drill
requires very little pressure and it operates efficiently, drilling both
soft and very hard rock, and it does not need sharpening. It extracts the
produced debris by transporting them up the drilling shaft. The instrument
is ideal for the exploration of other planets in space since it can operate
in a wide range of temperatures as well as a vacuum.
A more advanced drill model, called the ultrasonic gofer, is currently being
developed to reach depths of several meters, or yards. This deep drill will
be equipped with sensors that will make it even more effective for detecting
samples. These sensors will also analyze samples in-situ, meaning in its
location on a planet. Such a device could also be used on Earth to detect
buried objects and for geophysical studies.
Dr. Yoseph Bar-Cohen of JPL led the development team, which includes Drs.
Benjamin Dolgin and Stewart Sherrit, also of JPL, and the staff of
Cybersonics, Inc. in Erie, Penn. For more information, see
http://ndeaa.jpl.nasa.gov/nasa-nde/usdc/usdc.htm .
