In this study, Silicon Carbide (SiC) nanoparticle-based serigraphic printing inks were formulated to fabricate highly sensitive and wide temperature range printed thermistors. Inter-digitated electrodes (IDEs) were screen printed onto Kapton^® substrate using commercially avaiable silver ink. Thermistor inks with different weight ratios of SiC nanoparticles were printed atop the IDE structures to form fully printed thermistors. The thermistors were tested over a wide temperature range form 25 °C to 170 °C, exhibiting excellent repeatability and stability over 15 h of continuous operation. Optimal device performance was achieved with 30 wt.% SiC-polyimide ink. We report highly sensitive devices with a TCR of −0.556%/°C, a thermal coefficient of 502 K ($\beta$-index) and an activation energy of $0.08$ eV. Further, the thermistor demonstrates an accuracy of ±1.35 °C, which is well within the range offered by commercially available high sensitivity thermistors. SiC thermistors exhibit a small 6.5% drift due to changes in relative humidity between 10 and 90%RH and a 4.2% drift in baseline resistance after 100 cycles of aggressive bend testing at a 40° angle. The use of commercially available low-cost materials, simplicity of design and fabrication techniques coupled with the chemical inertness of the Kapton^® substrate and SiC nanoparticles paves the way to use all-printed SiC thermistors towards a wide range of applications where temperature monitoring is vital for optimal system performance.

Humidity sensors are essential components in modern technology, spanning applications from residential appliances to the Internet of Things (IoT). However, conventional commercial sensors are typically rigid, constrained by narrow relative humidity (%RH) operating ranges, and require complex fabrication processes. In this study, we present a highly sensitive cubic silicon carbide (3C–SiC) nanoparticle-based relative humidity sensor, fabricated via serigraphic printing on to 5 mil thick flexible polyimide (Kapton^®) substrate. Devices are tested across a broad humidity range of 10–90%RH at ambient temperature and their performance is evaluated in a controlled humidity chamber. The sensor exhibits a robust response of 45.2% R/R₀, with a sensitivity of 5.34 Ω/%RH, an adsorption time of 18 seconds, and a desorption time of 46 seconds. Additionally, the device demonstrates low hysteresis of 6.5% at 60%RH, with excellent repeatability and stability over 3.5 hours of continuous cycling. To showcase their potential for real-world applications, the printed sensors are integrated into a commercial KN95 mask for monitoring respiration parameters, such as respiration rate. This integration highlights the potential for future exploration in human health monitoring, utilizing fully printed, low-cost sensing devices.

Wide-bandgap tin oxide (${\mathrm{SnO}}_2$) thin-films are frequently used as an electron-transporting layers in perovskite solar cells due to their superior thermal and environmental stabilities. However, its crystallization by conventional thermal methods typically requires high temperatures and long periods of time. These post-processing conditions severely limit the choice of substrates and reduce the large-scale manufacturing capabilities. This work describes the intense-pulsed-light-induced crystallization of ${\mathrm{SnO}}_2$ thin-films using only 500 $\mathsf{\mu }\mathrm{s}$ of exposure time. The thin-films’ properties are investigated using both impedance spectroscopy and photoconductivity characteristic measurements. A Nyquist plot analysis establishes that the process parameters have a significant impact on the electronic and ionic behaviors of the ${\mathrm{SnO}}_2$ films. Most importantly, we demonstrate that light-induced crystallization yields improved topography and excellent electrical properties through enhanced charge transfer, improved interfacial morphology, and better ohmic contact compared to thermally annealed (TA) ${\mathrm{SnO}}_2$ films.