typically boost the thermal conductivity of the overall composite an order of magnitude beyond the base polymer (i.e., k ≈ 0.2 W m -1 K -1 for polymers). [5] Unlike curing TIMs, which exhibit elastomeric qualities due to cross-linking, noncuring TIMs can be dispensed, reworked, and remain in a fluid-like state under thermal cycling. The application-space for TIMs is large with varying requirements for mechancial, thermal, and other properties. For a detailed perspective on TIMs, we refer the reader to a number of review articles. [1,[5][6][7] Commercially available TIMs show modest thermal conductivity values that typically only range from 0.5-3 W m -1 K -1 despite containing high conductivity additives. [6] The relatively poor thermal transport through TIMs stem from a number of factors including interior thermal interface resistance between the polymer and filler particles, interior thermal interface resistance at filler-filler interfaces, and exterior thermal contact resistance to the TIM. [1,5,6] Increasing the filler volume fraction increases thermal conductivity, but is also subject to practical limitations as this reduces mechanical deformability and increases stiffness. Thermal transport percolation is achieved at critical volume fractions of solid fillers, which creates thermal transport pathways because high conductivity filler particles are in direct physical contact with one another. [8] However, percolated particles generally interface with each other through point-like contacts. This issue serves as a primary bottleneck for overall TIM thermal performance, independent of the filler materials employed. Physical joining methods such as welding or sintering of filler particles can increase the contact area between fillers for improved thermal transport. [9] However, forming these rigid connections requires additional processing steps and does not completely address the issue of composite stiffness for moderate to high filler loadings.Emerging TIMs consisting of room-temperature liquid metals (LMs) seek to improve the composite thermal conductivity by addressing the issues affecting thermal resistance and mechanical compliance. [7,10] Gallium-based LMs and its eutectic alloys (i.e., eGaIn and eGaInSn) have thermal conductivity values between 16-30 W m -1 K -1 depending on their elemental composition. [11] Unlike gallium which melts at 30 °C, both Thermal interface materials based on room temperature liquid metals (LMs) are promising candidates for improving thermal management of flexible electronics, microelectronics packaging, and energy storage devices. However, use of these materials is limited by their corrosivity and reactivity. Here, the fabrication and thermal characterization of multiphase soft composites consisting of LM and non-reactive silicon carbide (SiC) particles that are either uncoated or Ag-coated (Ag-SiC) are demonstrated. The LM-SiC (and LM-Ag-SiC) mixtures show thermal conductivities approaching 50 W m -1 K -1 at 40 vol% particles. Corrosion issues with aluminum-based components are...
