A Sub-nL Differential Scanning Calorimetry Chip for Liquid Crystal Phase Transition Characterization

This paper presents a sub-nL differential scanning calorimetry (DSC) chip for liquid crystal phase transition characterization. This is the first DSC chip capable of measuring a liquid sample at a sub-nL volume capacity. The chip achieves a heat-flow resolution of 6.29 nW, the highest among state-of-the-art demonstrations [1]. The chip features suspended twin membranes that house self-enclosed silicon nitride microchannels. The design realizes a low system heat capacitance of 2.3 μJ/K and thus minimizes the deformation in the DSC thermogram and the shift of transition temperature at an increased temperature scanning rate. Those distortions of the DSC measurement result have typically been observed at increased scanning rates for commercial DSC and other DSC chips. The compact chip comprises solid materials to facilitate measurement under low vacuum and offer superior sensitivity and low noise.