## 3 Results and Discussion  
To fabricate the new TIM structure, we used a PDMS matrix, TiO\({}_{2}\) NS-filler, and TiO\({}_{2}\) NS-monolayer. The detailed experimental condition and fabrication processes are described in the materials and methods section. To verify the morphology of the synthesized anatase TiO\({}_{2}\) NS, field emission scanning electron microscope (FESEM) measurements were conducted. The synthesized anatase TiO\({}_{2}\) NSs showed a spherical shape with diameters of several hundreds of nanometers, as shown in Figure 3a. The diameter distribution of the synthesized TiO\({}_{2}\) NSs is shown in Figure 3b, and the average diameter from the diameter distribution is about 352.25 \(\pm\) 20.7 nm, showing that the synthesized TiO\({}_{2}\) NSs have uniform sizes. Figure 2: Schematic of the fabrication process for the PDMS-based TIM with the TiO\({}_{2}\) NS-filler and monolayer. To observe the morphology changes of TiO\({}_{2}\) NS-based TIMs, FESEM measurements were conducted with various directions of the fabricated TIM samples, as shown in Figure 4. Figure 4a shows the transferred TiO\({}_{2}\) NS-monolayer on the rigid support substrate. Figure 4b,c shows the bottom view of PDMS with and without the TiO\({}_{2}\) NS-monolayer, respectively. As shown in Figure 4c, it can be confirmed that the TiO\({}_{2}\) NS-monolayer was successfully embedded in PDMS, which is clearly seen from Figure 4b. The loading fractions of the TiO\({}_{2}\) NS-filler in PDMS were adjusted to 20 wt%, 30 wt%, and 40 wt%, which can be converted to 5.3 vol%, 8.8 vol%, and 13.2 vol% as volume ratios, respectively. Figure 4d-f shows the FESEM cross-sectional images of the fabricated TIMs with different TiO\({}_{2}\) NS contents, and the occupancy of TiO\({}_{2}\) NS particles according to the change of loading fraction in PDMS can be roughly classified. From the cross-sectional views of the SEM, it should be noted that TiO\({}_{2}\) NSs are uniformly distributed inside the PDMS for all embedded conditions. The fabricated TIMs consisting of the TiO\({}_{2}\) NS-filler/monolayer embedded PDMS were attached to the actual GPU chipset to investigate the heat dissipation characteristics. Figure 5a shows the optical photographs of the GPU chipset, fabricated TIMs, heat sink, and cooling fan for the heat dissipation characteristic measurements. Figure 4: FESEM images of the (**a**) transferred TiO\({}_{2}\) NS-monolayer on the supporting substrate, bottom view of the PDMS (**b**) without and (**c**) with the TiO\({}_{2}\) NS-monolayer. (**d–f**) Cross-sectional images of the suggested TIM with TiO\({}_{2}\) NS-filler concentrations of (**d**) 20 wt%, (**e**) 30 wt%, and (**f**) 40 wt%. Figure 3: (**a**) FESEM image of the synthesized anatase TiO\({}_{2}\) NSs and (**b**) their size distribution histogram. The heat dissipation characteristics of the fabricated TiO\({}_{2}\) NS-based TIMs applied in the GPU chipset were compared by increasing the loading fraction of the TiO\({}_{2}\) NS-filler from 0 wt% to 20 wt%, 30 wt%, and 40 wt%, with and without the TiO\({}_{2}\) NS-monolayer. As shown in Figure 5b, the temperatures of the GPU chipset were gradually decreased with increasing loading fractions of the TiO\({}_{2}\) NS-filler from 0 wt% to 40 wt%. In addition, in all cases with the same filler loading fraction, the temperatures of the GPU chipset with the TiO\({}_{2}\) NS-monolayer embedded TIM were much lower than those of GPU TIMs without the embedded TiO\({}_{2}\) NS-monolayer. In all samples, the thermal conductivities of the TIMs were enhanced by the TiO\({}_{2}\) NS-filler, resulting in a lowered GPU chipset temperature from 62 \({}^{\circ}\)C to 55 \({}^{\circ}\)C with increasing loading fraction of the TiO\({}_{2}\) NS-filler from 0 wt% to 40 wt%.