PDMS Mold Optimization for Robotic Stacking

From MonArk NSF Quantum Foundry Knowledge Center
Jump to navigation Jump to search

PDMS Mold Optimization for Robotic Stacking

Overview

This process describes optimization of PDMS mold fabrication for robotic stacking applications in the MonArk NSF Quantum Foundry pipeline.

The goal is to identify the optimal PDMS volume range for:

  • Consistent nib formation
  • Reliable mold release
  • Reduced void formation
  • Improved transfer reproducibility

Applications

  • Robotic stacking
  • 2D material transfer
  • PC/PDMS stamp fabrication
  • Automated heterostructure assembly

Materials

  • PDMS mixture
  • Precision balance
  • Mold template
  • Glass substrate
  • SDS solution
  • Oven curing system

Experimental Results

PDMS Mass (mg) Observation Result
27 Too shallow, poor adhesion, large voids Failed
32 Contact with glass, center voids Failed
45 Smaller voids, first nib transfer Partial
50 Consistent nib formation Improved
62 Nearly filled mold, good meniscus Success
65 Stable mold formation Success
69 Stable mold formation Success
71 Stable mold formation Success
73+ Overfilling and failed mold removal Failed

Key Findings

The optimal PDMS mass range was found to be:

60–70 mg

This range produced:

  • Consistent nib formation
  • Reduced void density
  • Reliable mold release
  • Stable meniscus formation

Recommended Process

  1. Perform SDS pre-treatment
  2. Measure 60–70 mg PDMS
  3. Dispense PDMS into mold
  4. Inspect meniscus formation
  5. Cure mold
  6. Evaluate mold release quality
  7. Record success/failure rate

Failure Modes

Underfilling

Low PDMS masses caused:

  • Large voids
  • Poor glass adhesion
  • Incomplete nib transfer

Overfilling

High PDMS masses caused:

  • Difficult mold release
  • Distorted geometry
  • Delamination issues

Future Improvements

  • Controlled oven curing
  • Statistical success-rate analysis
  • Optical microscopy characterization
  • Automated PDMS dispensing