Model:
PDMS (Polydimethylsiloxane)
Main Components:
Silicone Rubber
Mechanism & Application Principle:
The core principle for SU-8 molding using PDMS lies in its low viscosity in the uncured state, which enables full conformal coating and structural filling on the SU-8 template surface. Meanwhile, its stable chemical properties ensure no corrosion or damage to the SU-8 template. After curing, PDMS exhibits excellent flexibility and mechanical strength to replicate SU-8 structures without destroying the original SU-8 mold. The prepared replica mold can be reused multiple times and features high optical transparency, as well as superior chemical and thermal stability.
Operating Procedure:
1、Surface Treatment: Treat the SU-8 template and its container (Petri dish) with a mold release agent.
2、Molding Agent Mixing: According to the template size, thoroughly mix the base material and curing agent of the molding agent at a 10:1 weight ratio in a beaker (centrifuge at 3000 rpm for 20 minutes to achieve complete mixing and preliminary degassing).
3、Complete degassing in a vacuum desiccator.
4、Casting & Final Degassing: Pour the PDMS molding agent onto the anti-adhesion treated SU-8 template placed in a Petri dish. Pouring the mixture from a low height onto the center of the template minimizes trapped air. Degas the mixture in a vacuum desiccator until no visible bubbles remain to remove any residual air bubbles. During this process, the molding agent will fully level on the SU-8 template surface, which also improves the filling of small structures. Keep the template horizontal throughout this step.
5、Curing: The PDMS molding agent can cure at room temperature within approximately 24 hours. To reduce curing time, place the Petri dish in an oven/hot plate at 80°C for at least 2 hours. Note that the molding agent undergoes significant shrinkage, up to about 3%.
6、Demolding: First release all edges, then continue peeling at a low speed along a direction parallel to most structures to remove the remaining portion.
Storage:
Ensure the workshop is equipped with adequate ventilation and exhaust systems;
Store in sealed, labeled containers in a cool, dry place;
Store separately from strong oxidizing agents;
Minimize release to the environment.
