Dear all,

I am having trouble with bubble formation whenever I attempt to cure a PDMS layer on a glass petri dish. To achieve a micro-textured layer of PDMS, I use a 3D-printed die with positive features. I maintain a 5:1 ratio of PDMS to curing agent and apply a coat of Mann Ease 200 spray onto the die, allowing it to sit for 15 minutes before placing it on the PDMS layer.

I utilize a vacuum to remove any bubbles that form while placing the die, and I cure it for 4 hours at 60°C. However, I still encounter numerous bubbles formed on the bottom surface of the PDMS layer.

Could someone suggest a method to address this issue?