Phenolic Resin Dual-Use Stamps for Capillary Stamping and Decal Transfer Printing

TL;DR

This paper introduces a novel porous phenolic resin dual-use stamp enabling both capillary stamping and decal transfer printing for precise, reusable micropatterning and functionalization in sensor applications.

Contribution

The study develops an optimized two-step thermopolymerization process to produce micropatterned porous phenolic resin stamps for dual additive manufacturing methods.

Findings

Enables non-destructive ink transfer via capillary stamping

Allows lithographic transfer of contact element tips for patterning

Facilitates functionalization of micropatterns for sensing applications

Abstract

We report an optimized two-step thermopolymerization process carried out in contact with micropatterned molds that yields porous phenolic resin dual-use stamps with topographically micropatterned contact surfaces. With these stamps, two different parallel additive substrate manufacturing methods can be executed: capillary stamping and decal transfer microlithography. Under moderate contact pressures, the porous phenolic resin stamps are used for non-destructive ink transfer to substrates by capillary stamping. Continuous ink supply through the pore systems to the contact surfaces of the porous phenolic resin stamps enables multiple successive stamp-substrate contacts for lithographic ink deposition under ambient conditions. No deterioration of the quality of the deposited pattern occurs and no interruptions for ink replenishment are required. Under high contact pressure, porous phenolic resin stamps are used for decal transfer printing. In this way, the tips of the stamps' contact elements are lithographically transferred to counterpart substrates. The granular nature of the phenolic resin facilitates the rupture of the contact elements upon stamp retraction. The deposited phenolic resin micropatterns characterized by abundance of exposed hydroxyl groups are used as generic anchoring sites for further application-specific functionalizations. As example, we deposited phenolic resin micropatterns on quartz crystal microbalance resonators and further functionalized them with polyethylenimine for preconcentration sensing of humidity and gaseous formic acid. We envision that also preconcentration coatings for other sensing methods, such as attenuated total reflection infrared spectroscopy and surface plasmon resonance spectroscopy, are accessible by this functionalization algorithm