Reinventing Advanced Cerametrics
ACI has evolved into a developer of new ceramic fiber technologies.
Richard Cass, Farhad Mohammadi, Ph.D., and Stephen Lschin
Andre Agassi uses a Head Intelligence series tennis racket powered by Advanced Cerametric Inc.'s self-powered piezoelectric ceramic fiber composites.
A dvanced Cerametrics Inc. (ACI), Lambertville, N.J., has developed a technology to produce ceramic fiber from nearly any ceramic material. These fibers possess the desirable properties of ceramics — such as thermal, chemical, electrical and mechanical properties — but mitigate the detrimental characteristics —such as brittleness and weight. ACI’s ceramic fiber technology has many novel applications including the ability to scavenge functional amounts of electric power directly from wasted mechanical energy, eliminating the need for batteries or power cabling in many systems.
The company adopted the name Advanced Cerametrics in 1991 to reflect its plan to enter into high-tech markets. ACI capitalized on its technical strengths and developed a range of new products starting with Conduxite, its patented, highly electrically conductive ceramic for use in electrochemistry. This led to the formation of HiTc Superconco, a wholly owned subsidiary, whose business model used ACI’s ceramic expertise to manufacture new ceramic high-temperature superconductor materials. The superconductor venture led ACI into the realm of high-tech research, and the company became an expert at winning Small Business Innovation Research grants and others from the US departments of Defense and Energy and the National Aeronautics and Space Administration. These grants permitted the company to develop a Viscous Suspension Spinning Process (VSSP) to form fibers from nearly any ceramic material. This patented process is the basis for many innovative fiber products, ranging from energy harvesting in sporting goods to reinforcement of bone scaffolds to solid oxide fuel cell separators.
Ceramic materials that have successfully been made into fiber form using ACI's process include: lead zirconate titanate for PZT-piezoelectric; titanium dioxide for batteries and water purification; yttrium-stabilized zirconium oxide for biomedical uses, fuel cells and ceramic and metal matrix composites; aluminum oxide for ceramic matrix composites; iron silicide for stealth applications; and calcium carbonate for paper applications; among many others.
Ceramic superconductors require extremely pure processing conditions. The first thought was to coat an organic fiber with a superconductor and then burn the organic fiber away. Carbon fiber was selected because it burns away as carbon dioxide and water, leaving no residuals in the crystal grain boundaries.
Superconducting tubes were produced, thus proving the concept. However, the tubes were too weak to be practical. Cass looked farther back into the fiber process to see how carbon fiber was made, with the idea of loading the carbon fiber precursor with the superconductor powder and then burning the precursor away.
Through pure serendipity, LCMC’s largest customer was Avtex Fibers Inc., Front Royal, Va. — the largest manufacturer at the time of carbon fiber precursor rayon fiber. LCMC convinced Avtex to load viscose with LCMC’s superconductor powder using LCMC’s new methods, and spin it as if it were rayon.
The concept worked. Once Avtex recognized the value of its rayon as a fugitive carrier for LCMC’s product, the idea of using the same machines and people to make $300-per-pound ceramic fiber versus 50 cents-per-pound rayon made sense.
After Avtex shut its doors in the late ‘80s, LCMC — soon to become ACI — worked with Germany-based BASF AG and then with Elizabethton, Tenn.-based North American Rayon Corp. as its viscose supplier.
ACI acquired Avtex’s pilot spinning line, made significant modifications to the rayon process and began spinning fiber in Lambertville. Using its modified process, ACI has been able to make ceramic fiber from rayon viscose, cellophane viscose, sausage casing viscose and sponge viscose.
ACI currently is investing significant monies to develop energy-harvesting technologies that will eliminate batteries in applications ranging from heart pacemakers that use pulse as the source of power to wireless sensor networks that use the activity being sensed as the source of power.
The company’s fibers are able to generate and store enough power to run small electronic systems from a few seconds of moderate-type vibrations. One example is the ability to power a soldier’s global positioning system from the vibrations of his steps while walking.
ACI also has developed a new generation of products that can produce light from mechanical energy directly without using any intervening electronics. An example is self-powered lights on navigation buoys that use rocking as the source of power, eliminating the use of batteries.
Self-diagnostic systems also are being realized. One example is a self-diagnostic bearing that uses ambient vibration to charge a radio frequency transmitter that relays information to a central data collection site, informing maintenance of the bearing’s health.
ACI’s Variable Diameter Fiber (VDF) technology has been shown to increase the absolute strength of reconstructive bone cement by a few percentage points. This is a good thing because one wouldn’t want new bone area to be significantly stronger than surrounding bone.
The company currently is focusing on producing piezoelectric fiber composites for energy harvesting, where it can harness ambient mechanical energy such as vibration to power electronic systems without the need for external power systems such as batteries. Self-powered sports computers using ACI’s piezo fiber composite power sources will be in stores in the summer of 2006.
Editors Note: Richard Cass is president; Farhad Mohammadi, Ph.D., is director, research; and Stephen Leschin is manager, business development, at Advanced Cerametrics Inc. November/December 2005