Engineering Commons^™

Effects Of Micro-Features On Cell Detachment From Poly(N-Isopropylacrylamide) Coated Polydimethylsiloxane Membranes, Luke Webel

Williams Honors College, Honors Research Projects

The tested hypothesis was that features on polydimethylsiloxane (PDMS) surfaces coated with a poly(N-isopropylacrylamide)/aminopropyltriethoxysilane or pNIPAAM/APTES thin film would accelerate cell detachment than the film coated on a unfeatured surface. This project tested samples with features generated by molds, wrinkling, and sandpaper roughened substrates. Surface feature generation methods were limited to mechanical means, and characterized by microscopy and strain rates. 50/50 mixtures of 1.5 wt.% pNIPAAM/ APTES were used to coat thin films (30-40 nm) on PDMS membranes by spin-coating, and the coated membranes were thermally annealed to chemically graft pNIPAAm/APTES on the membrane and their thermo-responsive property was assessed …

Wrinkling Of Membrane And Thin Film Under Torsion, Tingting Chen

Dissertations and Theses

Membranes and thin film structures are widely used in modern technologies. Applications include solar sails and sunshields in space missions, biological membranes and flexible circuit boards. Wrinkling of membrane or a stiff film on a soft substrate may occur in either desired or unwanted patterns. This work tries to obtain some understanding on the wrinkling phenomenon and provide guidance in avoiding wrinkling or effectively controlling the wrinkle patterns.

Many works have been published about wrinkling in the thin sheets since the 20^th century. However, there is no simple analytical way to systematically characterize the wrinkling in these studies. In …