Temperature-Sensitive Polymer Can Remember Four Different Shapes

Clockwise from top left: the polymer’s original shape at 140º, 107º and 68ºC. Image courtesy of Tao Xie, GM Research and Development Center

US polymer scientists Tao Xie has demonstrated how a polymer can assume up to four different shapes in response to temperature changes. The maximum number of shapes a shape-memory polymer could “remember” previously was three.

The research could lead to the development of novel smart polymers that can adopt a variety of shapes in response to specific temperatures. Potential applications cited by the scientists include biomedical engineering and space exploration.

Led by Xie, the scientists were able to achieve this breakthrough by heatling thin films of Nafion polymer and shaping it at a fixed temperature, after which the material was cooled. The researchers then repeated the procedure at other temperatures to form additional shapes. The polymer then could be coaxed to revert to the previous shapes in response to specific temperatures. Nafion can “remember” more shapes than other polymeric materials because of its wide transition temperature range, which is approximately 55 to 130°C, making more temperature options available.

Xie believes that an array of polymers with similar properties to Nafion also could be coaxed to assume a number of shapes in response to specific temperature stimuli.

More information on the research is available from RSC.

An abstract on the research is available on Nature.

Tags: GM, memory polymer, Nafion, Tao Xie