Unique Properties in Iridescent Wings of Tropical Butterfly key to highly selective Gas detection Sensors

Design and fabrication of highly selective vapour sensors inspired by Morpho butterflies. (a) Schematic of the tree-like tapered structure of natural butterfly scales with its chemical gradient of surface polarity. (b) Schematic of the fabricated nanostructure and design criteria for vapour-selectivity control. (c,d) Scanning electron microscopy (SEM) images of Morpho sulkowskyi scales and fabricated six-lamellae nanostructures. (e,f) Iridescent colouration of M. sulkowskyi scales and fabricated nanostructures. Shown in (f) are six regions of nanostructures that were fabricated with and without lamella; each region was 2 × 2 mm. On illumination with a white light, three replicate regions of nanostructures with lamella reflected blue light while three other replicate regions of nanostructures without lamella (with only ridges) reflected red light. Creidt: http://www.nature.com/ncomms/2015/150901/ncomms8959/fig_tab/ncomms8959_F1.html

Pioneering research by a team of international scientists, including University of Exeter, has replicated the surface chemistry in the iridescent scales of the Morpho butterfly to create an innovative gas detection sensor. The ground-breaking findings could inspire new designs for sensors that could be used in a range of sectors, including medical diagnostics, industry, and the military.

The composition of gases in different environments can be detected by measuring small colour changes of the innovative bio-inspired sensor. Tiny tree-like nanostructures in the scales of Morpho wings are known to be responsible for the butterfly’s brilliant iridescence. Previous studies have shown that vapour molecules adhere differently to the top of these structures than to the bottom due to local chemistry within the scales. This selective response to vapour molecules is the key to this bio-inspired gas sensor.

Results of modelling of vapour-response selectivity of the Morpho-like nanostructure. Credit; http://www.nature.com/ncomms/2015/150901/ncomms8959/fig_tab/ncomms8959_F2.html

The research team believe this highly selective colorimetric sensor could represent a significant advancement in gas leak detection performance in the future. “These new sensors not only selectively detect separate gases but also quantify gases in mixtures, and when blended with a variable chemical background. Our next goal is to make these sensors in a cost-effective manner to offer new attractive sensing solutions in the marketplace.” http://www.exeter.ac.uk/news/featurednews/title_468550_en.html