Modification of conformal-evaporated-film-by-rotation technique to improve uniformity of replicas of nonplanar biotemplates

摘要

We modified the conformal-evaporated-film-by-rotation (CEFR) technique to improve the uniformity of nominally ≤1000-nm-thick films deposited on nonplanar biological templates to replicate surface features. The biotemplates selected are eyes harvested from Phormia regina, a common species of blow fly which has large compound eyes. Bulk chalcogenide glass with nominal composition Ge_(28)Sb_(12)Se_(60) was used as the source material for all coatings. The modified CEFR technique introduced a second degree of freedom in manipulating the biotemplate with respect to the average direction of the vapor flux. We were thus able to tailor the motion of the platform holding the biotemplate to improve the uniformity of the coatings. Cross-sectional images of the coated biotemplates obtained using microtomy arid scanning electron microscopy confirmed the expected improvement.