Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Self-powered sensors

Abstract:
Harvesting electricity from small temperature differences could enable a new generation of electronic devices that don't need batteries.

By David L. Chandler, MIT News Office

Self-powered sensors

Cambridge, MA | Posted on March 10th, 2010

It can be inconvenient to replace batteries in devices that need to work over long periods of time. Doctors might have to get beneath a patient's skin to replace batteries for implanted biomedical monitoring or treatment systems. Batteries used in devices that monitor machinery, infrastructure or industrial installations may be crammed into hard-to-reach nooks or distributed over wide areas that are often difficult to access.

But new technology being developed by MIT researchers could make such replacements unnecessary.

Soon, such devices could be powered just by differences in temperature between the body (or another warm object) and the surrounding air, eliminating or reducing the need for a battery. They would use new energy-scavenging systems being developed by Anantha Chandrakasan, MIT's Joseph F. and Nancy P. Keithley Professor of Electrical Engineering and director of the MIT Microsystems Technology Laboratories, and Yogesh Ramadass SM '06, PhD '09.

Such a system, for example, could enable 24-hour-a-day monitoring of heart rate, blood sugar or other biomedical data, through a simple device worn on a patient's arm or a leg and powered by the body's temperature (which, except on a 98.6-degree F summer day, would always be different from the surrounding air). A similarly powered system could monitor the warm exhaust gases in the flues of a chemical plant, or air quality in the ducts of a heating and ventilation system.

The concept of harvesting energy from differences in temperature is nothing new. Many technologies for doing so have been developed, including devices NASA has used to power probes sent into deep space (the probes harvest heat from radioactive plutonium). Certain semiconductor materials, by their nature, will produce a flow of electrical current when one side is hotter than the other — or, conversely, will produce a difference in temperature when a current is run through them. Such materials are already used for solid-state coolers and heaters for food or beverages.

The principle was discovered in the 19th century, but only in recent years has it been seriously explored as an energy source. In thermoelectric materials, as soon as there is a temperature difference, heat begins to flow from the hotter to the cooler side. In the process, at the atomic scale this heat flow propels charge carriers (known as electrons or electron holes) to migrate in the same direction, producing an electric current — and a voltage difference between the two sides.

The key to making this principle practical for low-powered devices is to harness as much as possible of the available energy. Chandrakasan and Ramadass have been working to get as close as possible to the theoretical limits of efficiency in tapping this heat energy.

The higher the temperature difference, the greater the potential for producing power, and most such power-generating devices are designed to exploit differences of tens to hundreds of degrees C. The unique aspect of the new MIT-developed devices is their ability to harness differences of just one or two degrees, producing tiny (about 100 microwatts) but nevertheless usable amounts of electric power. The key to the new technology is a control circuit that optimizes the match between the energy output from the thermoelectric material and the storage system connected to it, in this case a storage capacitor. The findings were presented this week at the International Solid State Circuits Conference in San Francisco.

Because thermoelectric systems rely on a difference in temperature between one side of the device and the other, they are not usable for implanted medical devices, where they would be in a uniform-temperature environment. The present experimental versions of the device require a metal heat-sink worn on an arm or leg, exposed to the ambient air. "There's work to be done on miniaturizing the whole system," Ramadass says. This might be accomplished by combining and simplifying the electronics and by improving airflow over the heat sink.

Ramadass says that as a result of research over the last decade, the power consumption of various electronic sensors, processors and communications devices has been greatly reduced, making it possible to power such devices from very low-power energy harvesting systems such as this wearable thermoelectric system.

David Lamb, chief operating officer of Camgian Microsystems, a company that produces a variety of low-power, lightweight semiconductor chips, says that "we believe the wireless sensor products we are developing will all migrate to energy harvesting, as we push their size, weight and power down." He adds that the research of Chandrakasan and Ramadass "is in the critical path of technologies required by companies such as Camgian that are developing next-generation microsystems."

Devices to use this power would in most cases still need some energy storage system, so that the constant slow trickle of energy could be accumulated and used in short bursts, for example to operate a transmitter to send data readings back to a receiver. Different ways of storing the energy are possible, such as the use of ultracapacitors, Ramadass says. "These will play a critical role, in order to build a complete energy harvesting system," he says.

After years of work on these highly efficient energy-scavenging devices, currently funded by a seed grant from the MIT Energy Initiative, Chandrakasan says, "the time has come to find the real applications and realize the vision."

Read part two of this series, "Power from motion and vibrations."

web.mit.edu/newsoffice/2010/power-from-motion-and-vibrations.html

####

About MIT
The mission of MIT is to advance knowledge and educate students in science, technology and other areas of scholarship that will best serve the nation and the world in the 21st century — whether the focus is cancer, energy, economics or literature.

For more information, please click here

Copyright © MIT

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Conversion of Greenhouse Gases to Syngas in Presence of Nanocatalysts in Iran May 22nd, 2015

New Antibacterial Wound Dressing in Iran Can Display Replacement Time May 22nd, 2015

Haydale Named Lead Sponsor for Cambridge Graphene Festival May 22nd, 2015

Simulations predict flat liquid May 21st, 2015

Possible Futures

Simulations predict flat liquid May 21st, 2015

Nature inspires first artificial molecular pump: Simple design mimics pumping mechanism of life-sustaining proteins found in living cells May 19th, 2015

NNCO and Museum of Science Fiction to Collaborate on Nanotechnology and 3D Printing Panels at Awesome Con May 19th, 2015

Quantum 'gruyères' for spintronics of the future: Topological insulators become a little less 'elusive' May 12th, 2015

Academic/Education

SUNY Poly CNSE and NIOSH Launch Federal Nano Health and Safety Consortium: May 20th, 2015

New JEOL E-Beam Lithography System to Enhance Quantum NanoFab Capabilities May 6th, 2015

FEI Partners With the George Washington University to Equip New Science & Engineering Hall: Suite of new high-performance microscopes will be used for cutting-edge experiments at GW’s new research facility April 29th, 2015

Renishaw Raman systems used to study 2D materials at Boston University, Massachusetts, USA. April 28th, 2015

MEMS

Janusz Bryzek Joins MEMS Industry Group to Lead New TSensors Division - New Division will Focus on Accelerating Development of Emerging Ultra-high Volume Sensors Supporting Abundance, mHealth and IoT May 14th, 2015

Phonons, arise! Small electric voltage alters conductivity in key materials April 22nd, 2015

Iranian Scientists Evaluate Dynamic Interaction between 2 Carbon Nanotubes April 14th, 2015

ASIC Development for MEMS Applications: A Platform Approach March 25th, 2015

Chip Technology

Nanometrics Announces Live Webcast of Upcoming Investor and Analyst Day May 20th, 2015

Sandia researchers first to measure thermoelectric behavior by 'Tinkertoy' materials May 20th, 2015

Defects can 'Hulk-up' materials: Berkeley lab study shows properly managed damage can boost material thermoelectric performances May 20th, 2015

GLOBALFOUNDRIES Offers New Low-Power 28nm Solution for High-Performance Mobile and IoT Applications: Technology is the first in the industry to provide design enablement support optimized to meet low power requirements of RF SoCs May 20th, 2015

Nanomedicine

New Antibacterial Wound Dressing in Iran Can Display Replacement Time May 22nd, 2015

Researchers develop new way to manufacture nanofibers May 21st, 2015

Effective Nano-Micelles Designed in Iran to Treat Cancer May 20th, 2015

Nature inspires first artificial molecular pump: Simple design mimics pumping mechanism of life-sustaining proteins found in living cells May 19th, 2015

Sensors

Record high sensitive Graphene Hall sensors May 21st, 2015

Graphene enables tunable microwave antenna May 15th, 2015

Janusz Bryzek Joins MEMS Industry Group to Lead New TSensors Division - New Division will Focus on Accelerating Development of Emerging Ultra-high Volume Sensors Supporting Abundance, mHealth and IoT May 14th, 2015

Nano-policing pollution May 13th, 2015

Announcements

Conversion of Greenhouse Gases to Syngas in Presence of Nanocatalysts in Iran May 22nd, 2015

New Antibacterial Wound Dressing in Iran Can Display Replacement Time May 22nd, 2015

Haydale Named Lead Sponsor for Cambridge Graphene Festival May 22nd, 2015

INSIDDE: Uncovering the real history of art using a graphene scanner May 21st, 2015

Energy

Conversion of Greenhouse Gases to Syngas in Presence of Nanocatalysts in Iran May 22nd, 2015

Sandia researchers first to measure thermoelectric behavior by 'Tinkertoy' materials May 20th, 2015

Industrial Nanotech, Inc. Announces Official Launch of the Eagle Platinum Tile™ May 19th, 2015

FEI and Weatherford Enter Into Joint Agreement for Advanced Reservoir Characterization Services May 18th, 2015

Events/Classes

Haydale Named Lead Sponsor for Cambridge Graphene Festival May 22nd, 2015

Aspen Aerogels to Present at the Cowen and Company Technology, Media & Telecom Conference May 21st, 2015

Directa Plus in Barcelona to present the innovative project GEnIuS for oil spills clean-up activities: The company has created a graphene-based product for the remediation of water contaminated by oil and hydrocarbons May 21st, 2015

Nanometrics Announces Live Webcast of Upcoming Investor and Analyst Day May 20th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project