Taking their cue from nature's ingenuity, engineers have designed window fittings which can radically boost the energy efficiency and thermal control properties of built structures.

Ben Hatton, a professor of engineering at the University of Toronto, has collaborated with colleagues at Harvard University to devise a window which heightens the thermal regulation of building interiors via the emulation of vascular structures found in the organic world.

The fittings, described by Hatton and his research colleagues in a paper entitled “An artificial vasculature for adaptive thermal control of windows” and published by Solar Energy Materials & Solar Cells, consist of flexible and transparent elastomer sheets which can be attached to the glass panes of existing windows.

Hatton points out that around 40 per cent of building energy costs can be attributed to the presence of glass windows, thus providing green engineers with a ripe opportunity for enhancing thermal efficiency.

In tackling this problem, Hatton and his colleagues took their inspiration from nature, which over the course of countless eons has developed systems of peerless efficiency.

“In contrast to man-made thermal control systems, living organisms, have evolved an entirely different and highly efficient mechanism to control temperature that is based on the design of internal vascular networks,” Hatton said.

Bio inspired window illustrated

Bio Inspired Window

The polydimenthylsiloxane (PDMS) sheets created by Hatton and his colleagues are riddled with tiny channels which emulate the vascular systems of plants and animals and permit the passage of temperature.

Hatton says laboratory experiments have shown that this intricate network of water-engorged veins is capable of reducing indoors temperatures by as much as six degrees Celsius, on both small and large scales.

“Our results show that an artificial vascular network within a transparent layer, composed of channels on the micrometer to millimeter scale, and extending over the surface of a window, offers an additional and novel cooling mechanism for building windows and a new thermal control tool for building design,” he said.

According to the research, this method could also be used to enhance the energy efficiency of solar panels. A vascular system installed on the surface of solar panels can be used to heat water, which can then used for standard home purposes or employed in a heat storage system.