Thermochromic Plastic

by Tom Roberts
31 Jan 2013 / 4640 Views


Thermochromic Plastic 2.47/5 (19 votes)

The objective of this experiment was to mix thermochromic pigments with epoxy resin in order to create plastics with colour-changing properties.

Whilst previous tests were limited to single colours, in this experiment we mixed different pigments and staggered the temperature thresholds to achieve a gradation of colour changes. The first stage involved weighing-out a variety of ratios and colour combinations, taking care to mix the powdered pigments thoroughly to achieve a smooth gradation in the final products. Once satisfied with the mix, we added the pigments to the liquid resin and hardener before leaving them to set in shallow moulds under heating elements.

The thinner the plastic, the quicker the pigments respond to changes in temperature. At around 0.5cm in thickness, these discs responded quickly when heated with hot water and cooled with ice. Aesthetically, using running water to heat and cool the plastics gives the impression of coloured paints flowing over the surfaces of the discs. During the setting process the surfaces of the plastic discs also developed frothy ‘organic’ textures, reminiscent of pond scum.

The challenge for the near-future will be to experiment with forming techniques, and to control the colour changes (possibly using flowing water) in order to create larger ecologies of these responsive materials.

Participants: Manuel Kretzer (ETH, Responsive Design Studios), Hironori Yoshida (ETH), and Tom Roberts (University of Bristol).

21st – 25th of January 2103, at ETH Zürich, Switzerland.