Body Powered DevicesCody 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.