Finite differential hot-wire method for localized heat transfer characterization at microscale

In this work, we develop a finite differential hot-wire method to uncover the localized heat dissipation physics along microwires. The localized convection effect can be decoupled at the finite differential element with a spatial resolution of 10 microns. The heat convection coefficient is characterized from 314 W m−2 K to 1116 W m−2 K along different positions of microwires with different diameters, which decreases from wire ends to its middle point. The slope of temperature gradient at wire surface versus temperature is determined from 20150 m−1 to 8640 m−1, which can be used to calculate the boundary layer thickness around microwires.