While I have covered this topic many times before. 100's of "new" patents claiming to use this "new" technology.
Power harvesting research has delved into piezoelectric applications mainly due to the development of powerful new composite piezoelectric ceramic materials. The lead titanate zirconate group and even newer lead-free ceramic materials seem to show the most promise for future applications over a range of compositions. Flexible PVDF materials are even more intriguing.
History By request - Piezoelectricity is the term for electrical current generated by mechanical stress, or pressure, applied to certain non-conductive solids. The effect was first discovered by the Jacques and Pierre Curie brothers in the 1880's. The Curie brothers applied pressure to common crystalline materials, such as cane sugar, salt, and quartz, and found that electrical charges appeared, and these charges were proportional to the stress applied.
The latest research revolves around "power harvesting" from vibrations using piezoelectric materials (discussed in early article). Power harvesting is the term used to describe the process of acquiring the energy surrounding a system and converting it into usable electrical energy. This research has been sparked for the need for wireless power sources for the new wireless technology (WiFi laptop computers, Ipods, cell phones, etc.). However, this research has been into mostly low voltage applications.
Why old becomes "new" again. "The rules of physics are the same everywhere in the universe. The rules of men are different everywhere on Earth"
Ref (1) A Review of Power Harvesting from Vibration Using Piezoelectric Materials by H.A. Sodano, D.J. Inman and G. Park, Shock and Vibration Digest, Vol. 36, No.3, pgs 197-206 (2004).
Ref (2)Piezoelectric Ceramics by Hans Jaffe, Journal of the American Ceramic Society, Volume 41:11, Page 494, November, 1958.
Ref (3) Processing and Piezoelectric Properties of Lead-Free (K,Na) (Nb,Ta) 03 Ceramics, Journal of the American Ceramic Society, Volume 88:5, pages 1190-1196 (2005)
Ref (4) Content is available form PESWiki is an international Web-based free-content project under GNU Free Documentation License 1.2.