A low-temperature hydrogen sensor based on an acoustic topological material

Hydrogen, as a potential replacement for fossil fuels, exhibits promising application prospects and, meanwhile, demands hydrogen sensors with high performance due to flammability and explosivity. Currently, most of hydrogen sensors work based on sorption of hydrogen with hydrogen-sensitive materials. Thus, the sensitivities of the sensors decrease with operating temperature because the reaction between sensitive materials and hydrogen weakens. Here, we create a hydrogen sensor on the basis of an acoustic topological material, in which hydrogen can be detected by measuring the shift of the topological interface state. Owing to the absence of hydrogen sorption, the sensor possesses advantages of an extremely wide operating temperature range, a good linearity, a rapid and stable dynamic response, and a long life. It is demonstrated that the relative sensitivity of the sensor is a constant, which does not change with the operating temperature. This study opens an avenue to application of acoustic topological materials.