by Brian Buntz
Electroactive polymer technology could help engineers make lighter longer-lasting medical devices.
Brian Buntz 
Imagine a technology that could reduce the amount of energy used to power medical device applications by 25 to 100 times. An electroactive polymer (EAP) from Parker Hannifin’s BioCare business unit could do just that, says BioCare’sbusiness unit manager, Mario Calvo. The technology, which was on display at MD&M West, is a good fit for pumps and valves used in medical device applications and other relatively low-pressure and low-flow applications.
Measuring a fraction of a millimeter, the stretchable EAP film changes in size and shape when activated by an electrical field. “We are targeting battery activated devices where the patient is wearing, say, an oxygen tank, an infusion pump, or something of that nature,” Calvo says. “In many cases, 20–40% of the size of those device may be just the battery.” This EAPtechnology could enable medical devices to be lighter and quieter while lasting longer on the same-sized battery.
Other EAPApplications
The technology also can be used for drug-delivery and lab-on-a-chip applications. In the latter case, small amounts of fluid are used to do some mixing with the reagent. The EAP technology is so thin that it can fit onto a credit-card–sized template used for lab-on-a-chip analysis.
“The key value of EAP is that it is very flexible, stretchable thin material. Think of Saran wrap,” Calvo explains. It is unique in that it can conform to the body. “If you look at piezo or MEMS or other strain gauge technologies, they are all inflexible. You have piezo film technology that you can bend but you can’t stretch it.”
The ability of EAP to stretch is also useful in that the degree of movement can be correlated to bodily movement. When electroactive polymers’ shape is physically changed, their electrical characteristics also change, and that can be correlated to bodily movement, opening up applications in the wearables market segment.