Body Powered
Devices
Cody Goldberg
What?
• Devices powered by the energy the body produces.
• Generally thermo-conductive
• Other forms include mechanical, chemical.
• Increases in devices on/near body = increases in need for
more portable power.
• Batteries can only supply so much. More batteries provide
more weight and more $$$.
Thermo-conductivity
• Method of producing power by entropy gradient in
temperature.
• Gradient exists between skin, silicon contact, and
environment.
• Can convert 0.4% of heat energy into usable energy.
• TEGwear – commercial form of this technology.
• Expected consumer release in 2014.
• Outputs ~750 microwatts per square inch.
Uses
• Pacemaker
• Requires 1-20 microwatts.
• Can be powered by thermo-conductive power supplies.
• Mechanical Prosthetics
• Power differs with style of prosthetic.
• Initial burst of movement can be powered by stored capacitance
of power supply.
• Phones
• Most Li-ion phones require 2a for 100% charge in 1-3 hours.
• Conductive power supply can drip-charge Li-ion battery for longer
daily battery life.
Pros
• The many, many uses “free” energy can provide.
• Cheap, and many can be used in array.
• Lowers cost of existing solutions, and new solutions.
• Development of biomechanical devices may not need the same
battery/energy requirements as before.
Cons
• Provides a sensation of cold on application of conductive
square, as would touching your hand to a metal table.
• Requires environmental temperature to be colder than that of
your body.
• Arrays of device may prove to be too “cold” for users to
handle.
• Relatively new, early research was done in 2010. First
commercial device in 2014.
Future
• As with harnessing solar energy, these things take time.
• Conversion between states of energy is not perfected, nor
anywhere close to “good”.
• 0.4% conversion rate from heat to usable energy is bad, but can
become better.
References
• DOE/Lawrence Berkeley National Laboratory. "Body Heat To Power
Cell Phones? Nanowires Enable Recovery Of Waste Heat
Energy."ScienceDaily, 11 Jan. 2008. Web. 19 Nov. 2013.
• Dvorsky, George. "A Chip That Turns Your Body into a Battery." A
Chip That Turns Your Body into a Battery. Io9, 15 Jan. 2013. Web. 16
Nov. 2013.
• Ozcanli, Osman Can. "Turning Body Heat Into Electricity." Forbes.
Forbes Magazine, 08 June 2010. Web. 16 Nov. 2013.
• "TEGwear™ Technology." TEGwear™ Technology. Perpetua Power
Source, n.d. Web. 16 Nov. 2013.
• Wu, D. M., P. L. Hagelstein, P. Chen, K. P. Sinha, and A. Meulenberg.
"Quantum-coupled Single-electron Thermal to Electric Conversion
Scheme." Journal of Applied Physics 106.9 (2009): n. pag. AIP
Scitation. American Institute of Physics. Web. 16 Nov. 2013.