Polydimethylsiloxane (PDMS) is widely used in biomedical and microfluidic research platforms. However, its intrinsic hydrophobic nature hinders cellular attachment on the PDMS substrates. Surface modification is required to promote cellular attachment and growth. Corona discharge treatment offers a facile and robust technique for the PDMS surface modification. In this study, the effects of corona discharge treatment on the cellular attachment and morphology have been systematically investigated. The main conclusions are: (1) With the increase of corona discharge time, the contact angle and surface energy are significantly improved mainly because of the conversion of hydrophobic methyl groups into hydrophilic silanol groups. However, further increase results in deterioration of the surface wettability due to the cracks. (2) At an extremely thin sample of 0.1 mm, the contact angle is 22.7 degrees. At the sample thickness from 0.5 mm to 1.5 mm, the contact angle increases significantly from 4.6 degrees to 19.4 degrees. (3) With the increase of the corona discharge time and sample thickness, both the number of attached cells and aspect ratio increase significantly first and then decrease significantly. The optimal conditions observed are the sample thickness of 0.5 mm at the corona discharge time of 60 s.
