Liquidlike polydimethylsiloxane polymer brushes spontaneously delaminate drying protein-laden droplets

Surface deposition of the proteins present in body fluids plays a crucial role in contaminating medical devices and increasing the risk of infections. Here, the drying of bovine serum albumin (BSA) droplets on surfaces was studied, and the molecular brush conformation of polydimethylsiloxane (PDMS) was found to effectively limit protein adsorption in non-submerged conditions. At protein concentrations ≥2.00%, dried protein residues auto-delaminated from the surface of PDMS brushes, demonstrating self-cleaning functionality that was repeatable without fouling the surface. Lower concentrations did not auto-delaminate, due to surface-mediated denaturation of the proteins, but residues of such dried droplets were readily removable with a small puff of air. BSA droplets were able to recede from the surface of PDMS brushes, enabling a constant contact angle drying regime. PDMS brushes exhibited superior protein repellency compared to PDMS rubber as well as both perfluorinated brushes and perfluorinated self-assembled monolayers, demonstrating their potential for passive prevention of pathogen transmission. • Drying protein solutions auto-delaminate from grafted PDMS, leaving the surface clean. • Protein auto-delamination is concentration dependent. • The liquidlike nature of grafted PDMS chains suppresses the coffee ring effect. • Surface-mediated protein denaturation causes protein adhesion at low concentrations. • PDMS brushes are not cytotoxic.