Neurite development in PC12 cells cultured on nanopillars and nanopores with sizes comparable with filopodia

We investigated the effect ofnanoscale topography on neurite development in pheochromocytoma (PC12 cells) by culturing the cells on substrates having nanoscale pillars and pores with sizes comparable with filipodia. We found that cells on nanopillars and nanopores developed fewer and shorter neurites than cells on smooth substrates, and that cells on nanopores developed more and longer neurites than cells on nanopillars. These results suggest that PC12 cells were spatially aware of the difference in the nanoscale structures of the underlying substrates and responded differently in their neurite extension. This finding points to the possibility of using nanoscale topographic features to control neurite development in neurons.     

Enhanced Near‐Bandgap Response in InP Nanopillar Solar Cells

The effect of nanopillar texturing on the performance of InP solar cells is investigated. Maskless, lithography‐free reactive ion etching of InP nanopillars improves the open‐circuit voltage, reduces reflectance over a broad spectral range, and enhances the near‐bandgap response compared to a flat, non‐textured cell with comparable reflectance in the infrared. Electron‐beam induced current measurements indicate an increased effective minority carrier collection length. The response at short wavelengths decreases due to the formation of a defective surface layer with strong non‐radiative recombination. Plasma oxidation and wet etching partially restore the blue response resulting in a power conversion efficiency of 14.4%.