Fabrication of polydimethylsiloxane nano-hemispheres array for bio-application

We demonstrate an array of Poly(dimethylsiloxane) (PDMS) nano-hemisphere for colour separation by using soft lithography techniques. Each array of PDMS nano-hemisphere has an area of 1080 μm × 820 μm with well-defined period and diameter. The diameter of each nano-hemisphere and period between nano-hemisphere can be varied to produce the desired colour. The (periods and diameters) are (1400, 1120) nm, (1500, 1040) nm and (1600, 960) nm for red, yellow and green colours, respectively. The reflection spectrum obtained from coupling between an incident light and the nano-hemispheres array can be utilized for fluorescence spectroscopy as filters or spectral analysis for lab-on-a-chip (LOC) devices.