Characterization of surface heat convection of bilayer graphene

This paper studies the surface heat convection of a bilayer graphene and the possibility of using graphene wires as a flow and temperature sensor. A bilayer graphene wire was designed and fabricated, with the length of around 53 μm and the average width of around 0.5 μm. Prior to testing, the device was packaged with a microfluidic chamber and capillary tubes to minimize environmental interference. Thermal inertia of the graphene wire was studied at a temperature of 70 °C and the flow sensing behavior was characterized with normalized resistance changes for different values of flow rates. Our preliminary results demonstrate a negative temperature coefficient of the bilayer graphene and a flow sensitivity of about 0.44 L/min and a resolution of about 0.07 L/min. This technique provides a strong candidate for flow sensing in the nano and micro industrial applications with large temperature detection range, reliability and low cost.