An artificial vasculature for adaptive thermal control of windows


Hatton BD, Wheeldon I, Hancock MJ, Kolle M, Aizenberg J, Ingber DE. An artificial vasculature for adaptive thermal control of windows. Solar Energy Materials and Solar Cells. 2013;117 :429-436.


Windows are a major source of energy inefficiency in buildings. In addition, heating by thermal radiation reduces the efficiency of photovoltaic panels. To help reduce heating by solar absorption in both of these cases, we developed a thin, transparent, bio-inspired, convective cooling layer for building windows and solar panels that contains microvasculature with millimeter-scale, fluid-filled channels. The thin cooling layer is composed of optically clear silicone rubber with microchannels fabricated using microfluidic engineering principles. Infrared imaging was used to measure cooling rates as a function of flow rate and water temperature. In these experiments, flowing room temperature water at 2 mL/min reduced the average temperature of a model 10×10 cm2 window by approximately 7–9 °C. An analytic steady-state heat transfer model was developed to augment the experiments and make more general estimates as functions of window size, channel geometry, flow rate, and water temperature. Thin cooling layers may be added to one or more panes in multi-pane windows or as thin film non-structural central layers. Lastly, the color, optical transparency and aesthetics of the windows could be modulated by flowing different fluids that differ in their scattering or absorption properties.


BDH, IW,andDEIplannedtheresearch.BDHandIWfabricated devices andperformedtheexperiments.MKaidedinoptical transparencymeasurements.MJHdevelopedthetheoretical model. BDH,DEI,IW,JA,andMJHwrotethepaper.Allauthors revised thedocumentandagreedonits final contents.Wealso thank ShuyunWuforhisworkintheearlyphaseofthisproject.

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Last updated on 05/04/2018