MicroGen Chips to Power Wireless Sensors Through Environmental Vibrations

Via Daily Tech

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MicroGen Systems says its chips differ from other vibrational energy-harvesting devices because they have low manufacturing costs and use nontoxic material instead of PZT, which contains lead.

MicroGen Systems is in the midst of creating energy-scavenging chips that will convert environmental vibrations into electricity to power wireless sensors. 

The chip's core consists of an array of small silicon cantilevers that measure one centimeter squared and are located on a "postage-stamp-sized" thin film battery. These cantilevers oscillate when the chip is shook, and at their base is piezoelectric material that produces electrical potential when strained by vibrations. 

The current travels from the piezoelectric array through an electrical device that converts it to a compatible form for the battery. When jostling the chip by vibrations of a rotating tire, for example, it can generate 200 microwatts of power. 

Critics such as David Culler, chair of computer science at the University of California, have said that 200 microwatts may be useful at a small size, but other harvesting techniques through solar, light, heat, etc. are more competitive technologies since they can either store the electrical energy on a battery or use it right away. 

But according to Robert Andosca, founder and president of Ithaca, New York-based MicroGen Systems, his chips differ from other vibrational energy-harvesting devices because they have low manufacturing costs and use nontoxic material instead of PZT, which contains lead. 

Most piezoelectric materials must be assembled by hand and can be quite large. But MicroGen's chips can be made inexpensively and small because they are based on silicon microelectrical mechanical systems. The chips can be made on the same machines used to make computer chips. 

MicroGen Systems hopes to use these energy-harvesting chips to power wireless sensors like those that monitor tire pressure. The chips could eliminate the need to replace these batteries.

"It's a pain in the neck to replace those batteries," said Andosca. 

MicroGen Systems plans to sell these chips at $1 a piece, depending on the volume, and hopes to begin selling them in about a year.