Phys.org November 5, 2019
A team of researchers in the US (UCLA, Arizona State University, industry) has created, sunflower-like biomimetic omnidirectional tracker (SunBOT), an artificial phototropic system based on nanostructured stimuli-responsive polymers that can aim and align to the incident light direction in the three-dimensions over a broad temperature range. Such adaptive reconfiguration is realized through a built-in feedback loop rooted in the photothermal and mechanical properties of the material. They have shown that an array of SunBOTs can, in principle, be used in solar vapour generation devices, as it achieves up to a 400% solar energy-harvesting enhancement over non-tropistic materials at oblique illumination angles. The principle behind the SunBOTs is universal and can be extended to many responsive materials and a broad range of stimuli. Video …read more. TECHNICAL ARTICLE
SunBOTs can adaptively reconfigure to follow and to orient themselves perpendicular to the incident light from arbitrary and constantly varying directions (−150 to 150° zenith, 360° azimuth) at room temperature. Credit: Ximin He