Originally Published EMDM November/December 2001
INDUSTRY NEWS
Energy-Efficient Battery Runs on Body Heat
Benjamin Lichtman
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A
ceramic battery with a diameter of 0.5 in. can transform body heat into
electrical power.
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A
wafer-thin, fingernail-sized thermoelectric generator converts low-gradient
body-heat flow into electrical power that can be used to run embedded or attachable
medical devices. The half-inch-diameter ceramic battery does not contain any
chemicals and requires no replenishment, giving it potential applications in
wireless medical equipment.
Peter
Zhou is vice president and chief scientist at Applied Digital Solutions Inc.
(ADS; Palm Beach, FL, USA), the company that developed the battery. He explains
that while the technology behind the battery is not itself new, the fact that
it is miniaturized to this scale is a breakthrough. “The technology underlying
the generator has its roots in space exploration, where satellite applications
require long-lived batteries in a small package,” says Zhou, a physicist
who was educated at the Max Planck Institute (Stuttgart, Germany).
“Our
new approach has given a fingernail-sized battery that generates 1.5 V of electricity
at 10 µA, based on a 5°–10°F temperature gradient,”
he says, adding that the company will soon be able to produce a 3-V model using
the same technique.
ADS
originally developed the battery as a component for the company’s Digital
Angel technology platform. The Digital Angel product series, which was scheduled
to be launched this November, is described by the company as a “combination
of advanced biosensor technology and Web-enabled wireless telecommunications
linked to Global Positioning Systems (GPS).” The products are based on
portable devices that monitor patient vital signs and transmit these data, along
with a GPS signal, to remote monitoring centres. According to Zhou, the miniature
battery created so much interest that the company decided to introduce it as
a stand-alone product.
The
continuous body-heat battery has a wide variety of applications in implantable
and attachable medical devices, as well as wristwatches. Its small size makes
it an attractive power source in such devices. It is also a solid-state capacitor,
so it poses no danger of contamination or harmful interaction with the body.
And its dependence on body heat gives it the further advantage of reliability,
since it effectively eliminates the need to periodically replace power sources.
Or, as Zhou puts it, “As long as you’re alive, it’s always on.”
Because
of its low power output, the battery is best suited for noncontinuous operation
in devices such as alarms, where energy can be stored and released intermittently.
Nerve stimulation and other applications relying on “standby” devices
are also expected to benefit from the technology.
ADS is interested in licensing the battery to OEMs and is already in discussion
with medical manufacturers. Richard Sullivan, the company’s chairman and
CEO, says, “We’re looking forward to working with the medical community,
battery manufacturers, and other potential partners.”
For more information, contact Peter Zhou at Applied Digital Solutions Inc.,
400 Royal Palm Way, Ste. 410, Palm Beach, FL 33480, USA; phone: +1 561 8058000;
fax: +1 561 8058001; email: pzhou@adsx.com; Internet: www.adsx.com.
Copyright ©2001 European Medical Device Manufacturer
