Energy Harvesting and the Green

Here at Incredilution, we are always on the lookout for new and upcoming technologies to use in our client’s projects.    While energy harvesting is not new, many of the most promising concepts leverage cutting edge technology.

Energy harvesting is the process of capturing and storing ambient energy.  This energy can be in the form of radio waves, heat, vibration, wind, solar and  many others.  We are especially interested in harvesting techniques that can be leveraged for use in an embedded or small device environment.  Below we’ve identified some ideas worthy of further investigation and monitoring for improvements.

Piezoelectric

Here is a company that specializes in Piezo energy harvesting.  They use large piezoelectric elements with lever arms that vibrate at a specific, narrow band of frequencies to generate power.  Their units are relatively large for their power outputs and they must be used within certain narrow band frequencies.  However, this may be a good solution if your requirements fit within those constraints.


Solar

Just about everyone is familiar with solar technology using the standard monocrystaline silicon wafer (blue/green metalic look).  The problem with these is that usually they’re quite large for an embedded application.  Additionally they have very low output voltages making them tough to economically integrate into a design.  A company by the name of Clare (an IXYS Company) has taken a similar technology and repackaged it  in the form of an IC (integrated circuit) that can be directly soldered to a printed circuit board.  They’ve used new technology called silicon-on-insulator (SOI) to fabricate a tiny, yet high voltage solar cell.   We can take an array of these in parallel and build a very small device that is either solar assited or completely solar powered.  These ICs cost around $0.60 in quantities over 500.  In the world of energy harvesting, this is pocket change.

http://www.clare.com/Products/SolarCell.htm

Electroactive Polymer (Artificial Muscle)

EAP (electroactive polymers) material is quite neat.  They will change shape when a voltage (typically very high >1KV) is applied to them.  Depending on how the material is layered they can bend, contract, or turn into crazy shapes.  One of the technologies that falls under EAPs is dielectric elastomers.  These can also be used to generate power by flexing, bending, or streching the material.  There are thousands of applications for this type of energy harvesting.  One interesting one was the concept of sewing this material into a shirt.  The deflection of the material from normal human movement would generate a small amount of power.  Check out the link and video below:

http://www.artificialmuscle.com/applications/power_generation.html

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