Shape
memory polymers (SMPs) are an exciting class of stimuli-responsive
smart materials that demonstrate reactive and reversible changes in
mechanical property, usually by switching between different states
due to external stimuli. We report on the development of a polyurethane-based
SMP foam for effective pressure redistribution that demonstrates controllable
changes in dynamic pressure redistribution capability at a low transition
temperature (∼24 °C)—ideally suited to matching
modulations in body contact pressure for dynamic pressure relief (e.g.,
for alleviation or pressure ulcer effects). The resultant SMP material
has been extensively characterized by a series of tests including
stress–strain testing, compression testing, dynamic mechanical
analysis, optical microscopy, UV–visible absorbance spectroscopy,
variable-temperature areal pressure distribution, Fourier transform
infrared spectroscopy, Raman spectroscopy, X-ray diffraction, differential
scanning calorimetry, dynamic thermogravimetric analysis, and 1H nuclear magnetic resonance spectroscopy. The foam system
exhibits high responsivity when tested for plantar pressure modulation
with significant potential in pressure ulcers treatment. Efficient
pressure redistribution (∼80% reduction in interface pressure),
high stress response (∼30% applied stress is stored in fixity
and released on recovery), and excellent deformation recovery (∼100%)
are demonstrated in addition to significant cycling ability without
performance loss. By providing highly effective pressure redistribution
and modulation when in contact with the body’s surface, this
SMP foam offers novel mechanisms for alleviating the risk of pressure
ulcers.