Liquid Crystal Droplets as a Visualization Sensor of Heat Flux from Microfabricated Metal Structures

We propose a novel method of visualizing heat flux distribution from the microfabricated metal structures in MEMS devices using chiral liquid crystal (LC) droplets. We coat MEMS devices with 10μm-seized chiral LC droplets by controlling the temperature of chiral LC materials at chiral LC-isotropic (Iso) coexisting phase temperature. We found that chiral LC droplets convert the heat flux from the microfabricated metal structures into rotation of chiral LC droplets as a visualization sensor. Estimation of local heat flux in the MEMS devices by evaluating rotating characteristics performed successfully. The proposed novel method provides a simple solution to measure the localized heat flux distribution on patterned structures of MEMS devices independently of materials and geometry of devices.