Highly Sensitive Self‐Powered H<sub>2</sub> Sensor Based on Nanostructured Thermoelectric Silicon Fabrics
Mercè Pacios, Jose Manuel Sojo Gordillo, Hemesh Avireddy, Andreu Cabot, Àlex Morata, Albert Tarancón
Abstract
Abstract Self‐powered sensors running on small differences of temperature are considered promising candidates to cover the increasing demand of sustainable and maintenance‐free wireless sensor networks for the Internet of Things (IoT). Under this context, a cost‐effective and self‐powered hydrogen thermoelectric sensor is presented here as a proof of concept for battery‐less IoT nodes. The device is based on low‐density paper‐like fabrics made of functionalized thermoelectric silicon nanotubes able to harvest energy from the heat released by exothermic reactions, such as the hydrogen catalytic oxidation. This gives an accurate value of the reacting gas concentration without any external power requirement. Experimental results confirm that this self‐powered sensor can autonomously measure concentrations as low as 250 ppm of hydrogen in air while generating power densities up to 0.5 μW cm −2 for 3% H 2 at room temperature that can be eventually used to store or send the reading. Due to the universality of the concept, this new class of devices will positively contribute toward the development of other advanced self‐powered sensor nodes in the advent of the Internet of things to be used in different safety scenarios.