Hi,

Try using Toluene with PDMS while it is in liquid state. Optimize the mixing ratios of elastomer, curing agent and toluene while simultaneously tuning the spin coating RPM and acceleration (If the spin coater parameters are controllable). With this approach we could get somewhere around 1micron thickness relatively with an ease. One can even go below 1micron if the parameters are rigorously controlled!!!!!

Regards

Amit

You can dilute the PDMS, and then spin-coat the PDMS. It is difficult to obtain 5 um PDMS film using the original PDMS.

Using hexane to dilute your PDMS, mixing ratio 90% hexane and 10% PDMS.

You should be able to get around 1-2um thickness easily

fabricate a 5 um deep space on silicon then put PDMS on it, then press it to from.

which is capable of getting a more accurate and pure PDMS sheet.

Adding other solvent makes it not suit for biological applications.