Vigilancia Tecnológica

As is well known, the thermal conductivity of silicone gel is very low. However, alumina can improve the thermal conductivity of the parts of the thermal conductive network without CFs, that is, the silicone gel part. Uniform distributed alumina and silicone gel can be equivalent to a matrix, which means the heat diffusion effect of the matrix is improved. CF is known as the main pathway for heat transfer due to its high thermal conductivity (blue thick line). While spherical alumina, although lower in thermal conductivity than CF, is still higher than silicone gel. Alumina bridges the gap between oriented CFs, forming an efficient heat pathway in the orientation direction. So, alumina can assist in heat transfer (blue thin line). In this work, the high thermally conductive CFs, which are chosen to act as a main pathway to transfer heat flow, combine with spherical alumina to form a thermally conductive network. This strategic combination can greatly improve the thermal conductivity performance of thermal interface materials.AbstractCreating directional heat pathways within polymer?based elastomeric thermal interface materials (TIMs) using oriented thermally conductive fillers is an effective strategy for developing highly thermally conductive materials. In this work, we report the fabrication of oriented carbon fibers/alumina/silicone gel composites through a three?dimensional printing method. Because of the high orientation degree of carbon fiber (CF) in the vertical direction, the resulting material demonstrates a through?plane thermal conductivity of up to 27.77?Wm?1?K?1 with a composition of 21.75?wt% CF and 65.25?wt% spherical alumina, which is over 10 times higher than that of a parallel structure, surpassing the characters in most works of literature. In addition, the TIMs not only show outstanding flexibility (stress 62.27?psi at 30% strain) but also exhibit excellent resilience performance. These findings hold great potential for various scalable thermal and mechanical applications.