Skip to main content
. 2017 Dec 8;9(12):690. doi: 10.3390/polym9120690

Figure 5.

Figure 5

Characterization of PDMS spin-coating. (a) The thickness of PDMS film depended on spin-coating speed. The spin-coating speeds were 500, 1000, 2000, and 4000 rpm for 60 s. Each point on the plot corresponds to measurements on 25 samples from 5 rounds of fabrication. (b–e) SEM images measuring the uniformity of the PDMS film. (b) Uncured PDMS spin-coated with a thickness of 10 μm on a photoresist post with a height of 20 μm. (c) Uncured PDMS spin-coated with a thickness of 40 μm on a photoresist post with a height of 20 μm. The photoresist posts are not revealed on the surface due to the thick PDMS film. (d) Cured PDMS of (b) etched by 9% TBAF solution for 4 min. The PDMS in the nearby and far posts were thick and thin, respectively. Hence, we could not obtain a uniform PDMS film. (e) Cured PDMS of (b) etched by 9% TBAF solution for 10 min. Uniform PDMS film with holes could be obtained.