Darnell’s nanoPower Forum Highlights Maturity and Diversity

May 18, 2009 by Jeff Shepard

The first day of Darnell’s third-annual nanoPower Forum (nPF ’09) presented delegates with wide-ranging papers that demonstrated both the increased maturity of energy harvesting and thin-film battery technologies and the increasing diversity of applications employing those devices. Zhong Lin Wang, Director, Center for Nanostructure Characterization, Georgia Institute of Technology led off nPF ’09 with a lively and informative discussion of "Harvesting Mechanical Energy by Nanogenerators."

Like many of the presentations this year, Dr. Wang included demonstrations of actual harvesters, including videos of harvesting the energy of a running hamster and from the flexing of a human finger. He presented a detailed description of several new device types including: nanogenerators composed of piezoelectric (ZnO) nano-wires for harvesting energy, piezoelectric field effect transistors (FETs) and piezoelectric sensors.

Following Dr. Wang’s presentation, Randy Frank presented a paper on "Nanoelectronics: the European vision and strategy," that was co-authored by Giovanni Balli with the AutoGlobal Business Network in Italy. He presented the vision of the European Nanoelectronics Iniative Advisory Council (ENIAC) to "make the 2020 information society technologically feasible and economically affordable."

ENIAC is designed as an umbrella to guide definition and execution of all R&D in nanoelectronics in Europe, including all players (industry, academia and public authorities) and all mechanisms for public-private partnerships (national, transnational, and EC). Nanoelectronics, including energy harvesting and thin-film batteries are seen as key enabling technologies that will contribute to a competitive European electronics industry in the future. Targeted applications for nanoelectronics include communications, energy, medical, security, transportation, and so on.

Mark Buccini, Director with Texas Instruments spoke about and presented a demonstration of "Living Under 1 µW, Extreme Deeply Embedded Computing," and how to optimize the effectiveness of energy harvesting devices. He presented seven "principles for ultra-low-power embedded systems." Three of Buccini’s seven principles were: maximize the time in standby mode, optimize the power management of both internal and external peripherals, and effective code is a must (every unnecessary instruction executed is wasted energy that will never return).

Didier Sagan, Product Line Marketing Manager, Medical Products Group, Zarlink Semiconductor closed the plenary session discussing, "Wireless Body Area Network – Today and Tomorrow’s Potentials." He started by discussing miss-conceptions about the superior reliability of cables versus RF communications in body area networks (BANs), noting that cables are subject to a variety of mechanical stresses that can reduce their reliability and that cables can introduce signal integrity issues into designs.

He noted that power is a critical limiting factor in wireless BANs and stated that continued improvements in energy sources and power management will be important in determining the speed of adoption for BANs. According to Sagan, once sensors operate under 100-200 µW, the body can supply enough energy to eliminate the need for any type of battery. The challenge will be to produce thermo-electric harvesters that are small, efficient, comfortable to wear and cost-effective. The ability to store energy in thin-film batteries at the supply voltage (e.g. 1.2V), will eliminate unnecessary conversion steps and improve overall system efficiencies in BANs.