Microfluidic thermal flow sensor based on phase-change material with ultra-high thermal sensitivity

Abstract

A microfluidic thermal mass flow sensor based on planar micro-machining technology and a phase-change material is designed, fabricated, and characterized. The sensor configuration uses a small patch of vanadium dioxide...

Recent Advances of VO2 in Sensors and Actuators

“…Other applications considered in this review are a resistive photodetector [ 98 , 99 , 100 , 101 ], piezoelectric strain sensor [ 102 ], and thermal fluid flow sensor [ 108 , 109 ]. While the piezoelectric effect was observed in VO 2 , the application as a strain sensor is only theoretically proposed.…”

An Interesting Functional Phase Change Material VO2: Response to Multivariate Control and Extensive Applications in Optics and Electronics

“…When VO 2 is in the insulating phase, the intrinsic band gap is ≈0.67 eV [31] and the optical band gap is ≈2.5 eV, [32] and according to equation ( 6): (𝛼h𝜈) 2 = A(h𝜈-Eg), it can be seen that the wide optical bandgap leads to a low absorption coefficient of the infrared light, [31][32][33] and the existence of the intrinsic bandgap puts VO 2 in the insulating phase with few free carriers, which further reduces the light absorption, so that VO 2 (M) has a high IR transmittance [49] Copyright 2023, Royal Society of Chemistry. c) Refractive indices (n and k) of VO 2 film with 160 nm thickness deposited on glass, measured by ellipsometry.…”

“…Reproduced with permission. [ 49 ] Copyright 2023, Royal Society of Chemistry. c) Refractive indices (n and k) of VO 2 film with 160 nm thickness deposited on glass, measured by ellipsometry.…”

“…The thermochromic properties of VO 2 indicate a large temperature coefficient of resistance (TCR) near T C , which is attractive in the design of heat measurement. [ 49 ] The heat that affects the physical properties of VO 2 can be provided by photoirradiation, so VO 2 has become a new candidate material in the field of bolometer. Already in the last century, VO 2 ‐based bolometer arrays were reported.…”

“…Figure 3. a) Experimentally measured resistance of the VO 2 sensor as a function of temperature during the fully reversible heating and cooling cycle using substrate heating; b) Temperature-dependent TCR value of VO 2 in the major heating and cooling curves across the phase-change region. Reproduced with permission [49]. Copyright 2023, Royal Society of Chemistry.…”