LEIPZIG, Germany — A material specifically designed to control temperature within a silicone liner helped reduce moisture content and can enhance wearer comfort and reduce associated health concerns such as inflammation and wounds, according to study results presented here.
Phase change materials (PCM) change from solid to liquid and back again within certain temperature ranges, according to Barbara Pause, PhD, Textile Testing & Innovation LLC. When the material changes from solid to liquid, the PCM absorbs excessive heat while its temperature stays nearly constant. When integrated in a silicone liner, the material helps the microclimate temperature between the liner and the skin stay at a comfortable level over an extended time, which reduces perspiration.
The cooling effect depends on the latent heat storage capacity of the PCM, the PCM quantity in the liner, the trigger temperature and the product design, Pause said.
“What is important is that we need to select the phase change material that operates in the temperature range where we want to have the cooling feature,” Pause said.
In tests, researchers used paraffin as the PCM, which was added to two silicone liners, one of which contained 25% PCM by weight. Laboratory conditions reproduced a residual limb model walking at 3 km/hour, walking at a 10% slope, walking upstairs, and a perspiration environment. Test results showed the PCM material in the liners helped reduce the microclimate temperature by 4° to 6° and maintained a comfortable temperature (between 29°C and 32°C) for more than an hour of wear, Pause said. The PCM releases the stored heat when the liner is taken off, and remains stable after repeated wear.
“The latent heat absorption of the PCM integrated in the liner leads to a delayed increase in the microclimate temperature, reduced perspiration, and enhanced overall thermo-physiological wearing comfort,” Pause said.
The PCM integrated liners are currently being tested in amputees. “First results are coming out with users,” Pause said. — Carey Cowles
For more information:
Pause B. New prosthetic liners with thermo-regulating properties by the application of phase change material (PCM). Presented at: OT World Congress; May 12-16, 2014; Leipzig, Germany.
Disclosure: Pause has no relevant financial disclosures.