Sensors based on metamaterial absorbers are very promising when it comes to high sensitivity and quality factor, cost, and ease of fabrication. The absorbers could be used to sense physical parameters such as temperature, pressure, density as well as they could be used for determining electromagnetic properties of materials and their characterization. In this work, an attempt has been made to explore the various possible applications of these sensors. Metamaterial-based sensors are very popular for its diverse applications in areas such as biomedical, chemical industry, food quality testing, agriculture. Split-ring resonators with various shapes and topologies are the most frequently used structures where the sensing principle is based on electromagnetic interaction of the material under test with the resonator. Overcoming the design challenges using metamaterial sensors involving several constraints such as cost, compactness, reusability, ease in fabrication, and robustness is also addressed.

COVID-19 and its associated disease control measures have greatly altered everyday life. The burden of these challenges has fallen disproportionately on women. Drawing on qualitative inquiry in agrarian north India and Nepal, this research note analyzes how South Asian COVID-19 lockdowns have affected women's labor responsibilities in sometimes surprising ways. We find increased responsibilities for caregiving within the household, substantial stress in responding to food insecurity, and growing expectations to fulfill public roles in disease response measures. However, we also find that the return of male migrants and youth has, in some cases, reduced women's farming responsibilities and created opportunities for household togetherness at a time of great uncertainty. We conclude that more research is needed to examine the nuanced aspects of COVID-19's gendered labor impacts to create comprehensive policy responses to address the multiple and sometimes conflicting effects the lockdown has had on agrarian women's informal labor and well-being.

Methane is an important explosive gas, used extensively at the domestic and industrial sites. It is the main constituent of natural gas, which is the main fuel supplied to homes and industries including automobiles. Detection of trace level of methane gas is very important to avoid any accidental explosion due to its leakage and may cause loss of valuable human life and property. The present paper is focused on the development of new sensing material in the form of composites to improve sensitivity, selectivity and stability. Present work shows the enhanced response of SnO2-ZnO composite structures for methane sensing and further increases its sensing response by loading appropriate catalyst on the sensor surface keeping in view of Fermi energy control mechanism and spillover mechanism. A stable sensor response of 77-85 % was obtained for SnO2-ZnO-Pd sensor structure over a wider range of temperature (160-260oC).

In recent years, an increase in usage of methane gas in household and automobile industry has been observed. Detection of methane is always a great cause of concern for safety at home or automobile industries, productions in mines and chemical factories. This paper reports the response characteristics of rf-sputtered SnO2 thin films (90 nm thin) loaded with nanoscale catalytic clusters for detection of methane. Ultrathin (8 nm) metal and metal-oxide catalysts (Pt, Ag, Ni, Pd, Au, NiO, Au2O3) clusters are loaded over the surface SnO2 thin film. The SnO2-Pd cluster structure is found to exhibit an enhanced response (97.2%) for 200 ppm of methane at a relatively low operating temperature (220oC). The enhanced response is shown to be primarily due to the dominant roles played by both Fermi level energy control mechanism and spillover mechanism.

This paper reports the response characteristics of rf-sputtered SnO2 thin films (of varying thickness) for LPG detection. To monitor and precisely measure leakages, the development of a reliable LPG sensor with improved sensitivity is crucial in preventing fatal accidents. In the present study, thin film of SnO2 is used as the sensing element for LPG sensor. The thickness of a thin film is a very important parameter and determines their main operating characteristics, such as sensor response, rate of response, and working temperature. In the present study, thickness of SnO2 film is varied between 30 nm to 180 nm. The structure, composition and optical properties of SnO2 thin films have been examined by XRD, SEM, AFM and UV-Vis. The crystallite size for 90 nm thin film (for (110) plane) is found to be the smallest ~4-5 nm. Sensor response increases with thickness of the sensing film, with a highest sensor response (~67%) observed for 90 nm thin film and thereafter it decreases. The structural and optical properties clearly support the observed enhanced sensor response for 90 nm thin film.