Fabrication of metallic tube resonators and their applications on water boiling transition measurements

Abstract

Suspended microchannel resonators (SMRs) have been widely used to measure physical properties of materials but their fabrications entail complicated processes which need cleanroom facilities and high-end equipment. In addition, SMR devices have been utilized to measure changes in physical properties with elevated temperatures by globally heating the devices using external heaters. However, heater integrated SMR devices which realize an on-chip heating are too complex to be fabricated. This thesis reports an approach to realize an on-chip heating of SMR devices with alternative methods not using MEMS facilities. By clamping a straight stainless steel tube on jigs along with piezoelectric chips and set screws, an electrically heatable doubly clamped tube resonator is ready to be used. Basic resonant characteristics are investigated with a reference sample, DI water, using a lock-in amplifier for the first four flexural resonant modes. Then, various liquid samples of which densities range from 789 kg/m³ to 1490 kg/m³ are tested to measure their mass densities at room temperature. The resonator is heated using DC biasing and the boiling of water is measured by capturing the drastic increase of resonance frequencies. Stainless steel tube resonators are meaningful in that they realize an on-chip heating without microfabrication methods.