Strategic Polymer Sciences Inc. (SPS) has received a $1 million grant from the U.S. Dept. of Energy (DOE) to advance the development of its high-performance energy-storage DC bus-film capacitors, using SPS' proprietary high-temperature electroactive polymer (EAP) compositions. Considered a key component in the power management electronics of hybrid and plug-in electric drive vehicles, the current commercial polypropylene (PP) film DC capacitors cannot reliably operate above 105ºC, according to SPS. Since EDV engine radiator coolant temperature can go up to 125ºC, a secondary cooling system is required, but with SPS EAP films, which are extruded from proprietary blends of oriented fluoropolymers, the temperature stability is greater than 140ºC. SPS also notes that today's capacitors can occupy up to 35% of inverter volume, contributing up to 23% of the weight and adding up to 25% onto the costs.

SPS' EAP film.

In addition to use in power inverters for wind-turbine generators, grid-tied photovoltaics, and smart grids, SPS believes its high-performance EAP film capacitors could be applicable in pulsed power capacitors for medical cardiovascular defibrillators such as implantable and external automatic defibrillators, and capacitor banks for proton-radiation systems that treat cancer.

Founded in 2006 by Silicon Valley executive and investor Ralph Russo and Qiming Zhang, a polymer scientist from Penn State University, SPS develops new EAP materials and device technologies that are used in medical devices, energy storage, and military applications, working in conjunction with advanced polymer supplier, Solvay. In addition to dielectric films for advanced capacitors, the company also creates oriented fluoropolymer films that exhibit state-of-the-art actuation capabilities without the need for electrolytes. Exhibiting 70 times the strain response of other piezoelectronic actuator materials while operating at lower voltages than competing piezoelectric films, these materials are targeting the medical device market where microsteerable cardiac ablation catheters using these films could make lifesaving treatments for atrial fibrillation easier, safer, cheaper, and more effective than existing systems.