Compressive mechanical response of graphene foams and their thermal resistance with copper interfaces

TL;DR

This study investigates the compressive mechanical properties and thermal resistance of graphene foams with varying densities, revealing power-law relationships and the impact of density on energy absorption and thermal interface resistance.

Contribution

It provides new insights into how the density of graphene foams influences their mechanical response and thermal interface resistance with copper, using CVD-prepared samples.

Findings

Young's modulus and compressive strength follow power-law dependence on density.

Maximum energy absorption efficiency exceeds 0.39 for all GFs.

Thermal resistance increases with higher foam density.

Abstract

We report compressive mechanical response of graphene foams (GFs) and the thermal resistance ($R_{TIM}$) between copper (Cu) and GFs, where GFs were prepared by the chemical vapor deposition (CVD) method. We observe that Young's modulus ($E_{GF}$) and compressive strength ($\sigma_{GF}$) of GFs have a power law dependence on increasing density ($\rho_{GF}$) of GFs. The maximum efficiency of absorbed energy ($\eta_{max}$) for all GFs during the compression is larger than ~0.39. We also find that a GF with a higher $\rho_{GF}$ shows a larger $\eta_{max}$. In addition, we observe that the measured $R_{TIM}$ of Cu/GFs at room temperature with a contact pressure of 0.25 MP applied increases from ~50 to ~90 $mm^2K/W$ when $\rho_{GF}$ increases from 4.7 to 31.9 $mg/cm^3$.