In vivo skin thermophysical property testing technology using flexible thermosensor-based 3ω method

Abstract

Highlights In vivo skin thermophysical property testing sensor without damage to the skin. Finite element analysis to extract thermal conductivity information of skin layers. Skin thermal conductivity information is highly correlated with skin health.

High Performance Acoustic Wave Nitrogen Dioxide Sensor with Ultraviolet Activated 3D Porous Architecture of Ag-Decorated Reduced Graphene Oxide and Polypyrrole Aerogel

“…Intelligent monitoring and wireless sensing technologies have been developed extensively with the rapid progress of internet of things (IoTs), and smart sensors are one of the crucial components which are necessary to collect massive amounts of data and information from surrounding environments. − For example, toxic and irritant nitrogen dioxide (e.g., NO 2 ) is one of the common air pollutants contributing to the formation of ground-level ozone and acid rain, and it is also harmful to human health and terrestrial plants. , Therefore, it is important to develop a wirelessly operated gas sensor integrated with the IoTs for rapid and selective detection of NO 2 at room temperature. A surface acoustic wave (SAW) sensor, which has been widely used to detect physical, chemical, and biological substances, offers the possibility of realizing highly sensitive NO 2 sensors with a low detection limit (simply because the energy of the acoustic waves is concentrated on or near the sensing surface of the SAW device). − The resonant frequency signals of the SAW device can be transmitted wirelessly, supporting the possibility of remote sensing, and also can be installed at different places under harsh conditions. , …”

Significantly Enhancing Mechanical and Thermal Properties of Cellulose-Based Composites by Adding Small Amounts of Lysozyme-Modified Graphene Nanoplatelets via Forming Strong Double-Cross-Linked Interface Interactions

“…The in-plane TC of the composites was measured by Hot Disk and the through-plane TC was determined by the 3ω method Figure a shows that the in-plane TC of PC was 0.841 W·m –1 ·K –1 , and the through-plane TC was 0.715 W·m –1 ·K –1 .…”

“…Furthermore, the composites' tensile strength and Young's modulus were characterized by a universal testing machine (ZQ950B, Guangdong Intelligent Precision Technology Co., Ltd., China) with a tensile rate of 1 mm/min at room temperature. The inplane TC and specific heat of the composites were characterized by a thermal constant analyzer (TPS 2500 S, Hot Disk, Sweden), and the through-plane TC was tested and calculated by the 3ω method, 51 and the details are shown in the SI. The TG properties of composites were determined by a thermal analysis platform (Abyss Evo, Setaram, France) at a heating rate of 10 °C/min from 25 to 700 °C under a nitrogen atmosphere.…”

“…The in-plane TC of the composites was measured by Hot Disk and the throughplane TC was determined by the 3ω method. 51 Figure 4a shows that the in-plane TC of PC was 0.841 W•m −1 •K −1 , and the through-plane TC was 0.715 W•m −1 •K −1 . Under the chemical cross-link effect of ECH, no significant anisotropy of TC can be found compared to the work of other researchers.…”

Variations of skin thermal diffusivity on different skin regions

“…Numerous devices have been proposed in the literature to measure the thermal properties of the skin in vivo 10–26 . More recently, wearables have emerged as a solution for continuous monitoring 27–37 . However, to date, only a few studies have been devoted to investigating the potential correlation between thermal parameters and relevant physiological value.…”