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White butterflies as solar photovoltaic concentrators.

Shanks K, Senthilarasu S, Ffrench-Constant RH, Mallick TK - Sci Rep (2015)

Bottom Line: Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application.Moreover, a single mono-layer of scale cells removed from the butterflies' wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating.As predicted, the wings increased the temperature of the butterflies' thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off.

View Article: PubMed Central - PubMed

Affiliation: Environment and Sustainability Institute, Biosciences, University of Exeter, Falmouth, TR10 9FE, UK.

ABSTRACT
Man's harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies' wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies' thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off.

No MeSH data available.


Related in: MedlinePlus

Reflectance mapping method.(a), Photograph of forewing placed against integrating sphere at the third measurement position of 8 mm along and 1 mm up (position C). (b), An indication of the limit of measurements due to porthole size represented by the yellow dotted circles. (c), The full mapping technique with position labels. The exact location of incident beam is not known but confined to the rectangles labelled alphabetically in order of measurements taken.
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f5: Reflectance mapping method.(a), Photograph of forewing placed against integrating sphere at the third measurement position of 8 mm along and 1 mm up (position C). (b), An indication of the limit of measurements due to porthole size represented by the yellow dotted circles. (c), The full mapping technique with position labels. The exact location of incident beam is not known but confined to the rectangles labelled alphabetically in order of measurements taken.

Mentions: The reflectance was measured over the wavelength range of 300–1750 nm using a Bentham PVE300 system, the maximum and minimum reflectance spectra are shown in Fig. 3 for the small white, large white and green veined butterfly wing samples. Within this range a wavelength interval of 5 nm was taken and by moving across the wing (x-axis) and up the wing (y axis) in 2 mm steps, the wing was manually mapped as shown in Fig. 5 b,c. The response of the monocrystalline silicon cell (1 cm × 1 cm) was also measured using the Bentham and the external quantum efficiency (EQE) plotted in Fig. 3 graphs a to c, to show the wavelength compatibility between the reflectance spectra of the butterfly wing and working range of the solar cell.


White butterflies as solar photovoltaic concentrators.

Shanks K, Senthilarasu S, Ffrench-Constant RH, Mallick TK - Sci Rep (2015)

Reflectance mapping method.(a), Photograph of forewing placed against integrating sphere at the third measurement position of 8 mm along and 1 mm up (position C). (b), An indication of the limit of measurements due to porthole size represented by the yellow dotted circles. (c), The full mapping technique with position labels. The exact location of incident beam is not known but confined to the rectangles labelled alphabetically in order of measurements taken.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4521190&req=5

f5: Reflectance mapping method.(a), Photograph of forewing placed against integrating sphere at the third measurement position of 8 mm along and 1 mm up (position C). (b), An indication of the limit of measurements due to porthole size represented by the yellow dotted circles. (c), The full mapping technique with position labels. The exact location of incident beam is not known but confined to the rectangles labelled alphabetically in order of measurements taken.
Mentions: The reflectance was measured over the wavelength range of 300–1750 nm using a Bentham PVE300 system, the maximum and minimum reflectance spectra are shown in Fig. 3 for the small white, large white and green veined butterfly wing samples. Within this range a wavelength interval of 5 nm was taken and by moving across the wing (x-axis) and up the wing (y axis) in 2 mm steps, the wing was manually mapped as shown in Fig. 5 b,c. The response of the monocrystalline silicon cell (1 cm × 1 cm) was also measured using the Bentham and the external quantum efficiency (EQE) plotted in Fig. 3 graphs a to c, to show the wavelength compatibility between the reflectance spectra of the butterfly wing and working range of the solar cell.

Bottom Line: Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application.Moreover, a single mono-layer of scale cells removed from the butterflies' wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating.As predicted, the wings increased the temperature of the butterflies' thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off.

View Article: PubMed Central - PubMed

Affiliation: Environment and Sustainability Institute, Biosciences, University of Exeter, Falmouth, TR10 9FE, UK.

ABSTRACT
Man's harvesting of photovoltaic energy requires the deployment of extensive arrays of solar panels. To improve both the gathering of thermal and photovoltaic energy from the sun we have examined the concept of biomimicry in white butterflies of the family Pieridae. We tested the hypothesis that the V-shaped posture of basking white butterflies mimics the V-trough concentrator which is designed to increase solar input to photovoltaic cells. These solar concentrators improve harvesting efficiency but are both heavy and bulky, severely limiting their deployment. Here, we show that the attachment of butterfly wings to a solar cell increases its output power by 42.3%, proving that the wings are indeed highly reflective. Importantly, and relative to current concentrators, the wings improve the power to weight ratio of the overall structure 17-fold, vastly expanding their potential application. Moreover, a single mono-layer of scale cells removed from the butterflies' wings maintained this high reflectivity showing that a single layer of scale cell-like structures can also form a useful coating. As predicted, the wings increased the temperature of the butterflies' thorax dramatically, showing that the V-shaped basking posture of white butterflies has indeed evolved to increase the temperature of their flight muscles prior to take-off.

No MeSH data available.


Related in: MedlinePlus