In TME (Transparent Mold Embossing) technique, carbon black modified PMMA and HDPE (carbon black content is 0.5%) were used as the substrate that can absorb heat from the laser source. After the heating stopped, the mold was pressed down to transfer the pattern onto the substrate. After holding/cooling, the mold was separated from the substrate.
In TSE (Transparent Substrate Embossing) technique, a transparent PMMA substrate was used, which allowed IR laser radiation to pass through and heat the mold. The mold was made of epoxy blended with 2% carbon black to allow it to absorb the energy from the laser source. The embossing force was applied while the heating began. When the desired pattern was transferred from the mold to the substrate, the radiation was discontinued. After holding/cooling, the mold was again separated from the substrate.
Simulation of LIME
Model
Figure 1 Feature Figure 2 Model
The mold has a dog-bone shaped feature that can generate two reservoirs connected with one channel on the substrate after embossing.
Heat transfer
Heat absorbing rate at different z equals  , where I is the incident laser power density at different z and  , where  is the coefficient of absorption of the substrate material that can be calculated from the transmittance data as shown in Figure 3 (a) and the measured laser power distribution as shown in Figure 3 (b).
Figure 3 (a) Transmission test (b) Power distribution
Simulation result of TSE
In TSE, a HAZ (Heat affected zone) is shown in Figure 4 because the heat absorbed by the mold as shown in Figure 5 was transferred to the substrate via conduction through the contacted area, which resulted in a squeezed flow shown in Figure 6 and Figure 7. A comparison between simulation and experimental results were made and shown in Figure 8 and Figure 9.
Simulation result of TME
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