Rolling V-groove microstructures on glass using a modified PDMS mold

Unlike polymers, glass is prone to fracturing under localized stress during roll embossing. Molds traditionally used for glass embossing are rigid and unsuitable for roll embossing. In this investigation, we utilized a modified soft polydimethylsiloxane (PDMS) mold, known for its ease of fabrication and superior replication capacity, for roller embossing on glass. This innovation significantly cuts mold expenses while preserving PDMS’s hydrophobic and low surface energy attributes. Consequently, it prevents adhesion between the glass and the mold during high-temperature embossing, ensuring that the demolding process does not harm the glass surface. We successfully carried out roll embossing on optical glass with a mere 1.65 mm thickness, using a self-devised stainless steel carrier plate and a mobile induction heating apparatus. This heating methodology departs from the conventional practice of employing multiple heat sources in glass embossing and instead uses a singular heat source. Induction heating is applied directly to the mold and 420 stainless steel carrier. The optical glass surface reaches a remarkably uniform temperature, with a minimal temperature differential of only 2.5 °C, which is highly advantageous for mobile roller embossing, resulting in a high replication rate of V-groove microstructures on glass.