Thin-Film Thermistor Temperature Sensors on Animal-Based Substrates

Materials and technology advancements have enabled the development of thin-film electronics on substrates that were previously unsuitable. This article reports on the potential of using animal-based substrates, including buffalo horn (BH) and mother of pearl (MP), to fabricate negative temperature coefficient thermistors (NTC). The thermistors were fabricated using sputtered Zn metal and IGZO semiconducting thin-films. The conformal sputter deposition allowed the realization of functional devices on uneven natural substrates. The thermistors' performance was investigated using a localized heater on top of the sensor and cycling the temperature between 25 °C and 80 °C. The thermistors show reliable performance over multiple temperature cycles but also a large hysteresis. For increasing temperatures, the sensitivity of the two thermistors in the linear range varies between 0.22%°C-1 and 0.16%°C-1 for the BH and MP substrates, respectively. Being naturally eco-friendly and compatible with vacuum deposition techniques, animal-based materials can offer promising natural eco-friendly substrates for temperature sensors, resulting in less hazardous electronic waste, as well as sensor interfaces on aesthetically pleasing surfaces.