Fig. 3.

a We identified an arc-like structure (b) resulting from the deflection of the chip and measured it in terms of the distance between the top of the arc and the heating surface (maximum distance between the two surfaces). The deflection resulted in a temperature drift within the deflected chip which we measured at 3 different temperature points – 98C, 72C and 60C. We selected these values based on the typical temperature used in 3-step PCR. d The plasma treatment of the PDMS surface resulted in minimized oil loss regardless of glass thickness. The reduction in oil absorption into the PDMS prevents its contribution to the warping problem