Self-powered systems -- can they eliminate the need for batteries?

Smart Structures: Active fiber composites also offer solutions for vibration damping and structural morphing. To enable self-adjusting systems, a smart structure containing Active fiber composites senses a change in motion. The motion produces an electrical signal that can be sent to a control processor that measures the magnitude of the change in motion and returns an amplified signal that either stiffens or relaxes the active fiber actuators/sensors. Just a 2 gram AFC can create a 60lb blocking authority!

Design integration
The key integrating PZT fiber technology into your own end system is determining your power requirements and understanding and tapping the available mechanical energy. The design process includes these key steps:

1. Determine energy needs: What are the energy requirements of the system you need to power? Power in the world of EH needs to be balanced and kept in the positive just like a checkbook.

2. Inventory ambient power sources available: The application of your device will help determine available locations, i.e. machines, structures, vehicles, human, etc. Once you define the application, the sources of local vibration or mechanical energy need to be quantified.

3. Determine physical packaging requirement: How much room does your application allow for piezoelectric fiber composites? If it’s a portable electronic device, the area doesn’t have to be limited by the size of the battery compartment. Indeed, the piezo composites may take the shape of the device itself.

4. Model piezo power capability: Piezoelectric power output can be determined once the size and form factor of the composite are determined and mechanical forces and frequencies are known. A prototype will need to be built for your application to ensure success in a real-world environment.

5. Determine rectification, storage, and regulator needs: The electronics design is relatively simple for energy harvesting. The key requirements are power storage, regulated voltage, and tolerances.

EH system checklist:

Summary
There are an emerging number of new and unique products coming to market that are limiting or obviating the need for batteries. Piezoelectric ceramic fiber technology provides a unique solution for EH, active structural control, and self-powered electronic systems. Active fiber composites by ACI have 10x the power output of other piezo forms, and have typical durability of 200 million cycles. By combining fiber composites with low-cost electronics and packaging, a new era of ultra low power products and applications is dawning. New market solutions are emerging that offer an ELSP Factor for low power applications that is battery free.

About the Authors
John Marciszewski is currently a Management Consultant with Advanced Cerametrics Inc. John Marciszewski has 20⁺ years experience in semiconductors, networking, and consumer electronics. John was most recently VP at Conexant Systems Inc. and previously held executive positions at NCR and AT&T’s Bell Laboratories. John holds a M. Eng. (EE) from University of CA, Berkeley, and Bachelor of Science (ME, EE), from General Motors Institute (Kettering University), Flint, MI.

Steve Leschin is Managing Director of Business Development at Advanced Cerametrics Inc. Steve started his career at Rockwell Automation’s Reliance Electric group. At Emerson Electric Company, Steve held senior executive positions and was responsible for the company’s global focus on Networked Power solutions. At American Power Conversion Steve was Director, Asia Pacific and General Manager, Japan. Steve received his Bachelor of Science in Engineering from Iowa State University in Ames, Iowa. You can contact Steve at steve.leschin@advancedcerametrics.com or go to the company website at www.advancedcerametrics.com