Quick MSL recipe for PDMS micromolds

Quick SOP Soft lithography – PDMS molds  – January 2023, A. Blednov

This is the most common recipe used in the Michael Smith Laboratory soft lithography cleanroom.

  • Mix 6g curing agent with 54g of elastomer base into the single use cup
  • Cup + mixture total weight should equal 260g
  • NB: if total weight is different, adjust mixer to appropriate counter balance
  • Put in mixer and use the automatic recipe (60s mixing + 120s foaming)
  • Put cup in degas chamber
  • Follow steps written on chamber to evacuate the degas chamber
  • Leave in degas chamber until bubbles no longer visible on top of mixture (at least 1hr)
  • In a plastic petri, place micro-mold and pour degassed mixture on top of micro-mold
  • Put in the 80°C incubator for curing (at least 1 or 2 hours)
  • Take out and peel PDMS layer from micro-mold
  • Place PDMS, pattern up, and glass substrate in the oxygen plasma chamber
  • Pump down plasma chamber to 300 mTorr
  • Introduce oxygen to 650 mTorr pressure
  • Turn plasma power to high for 30s
  • Open plasma chamber and immediately put together the PDMS and the glass substrate
  • Place device in 80°C incubator for 1 hour