Ultrasensitive piezoelectric sensor based on two-dimensional Na2Cl crystals with periodic atom vacancies

Abstract Pursuing ultrasensitivity in pressure sensors that offer precise mechano-electric transduction of tiny mechanical stimuli under complex ambient conditions, is of great importance and has been a long-standing goal¹⁻¹⁰. The introduction of microstructures at micro- and nano-scale, can effectively improve the sensitivity, detection limit, and pressure-response range due to their structural asymmetries and compressibility⁵,⁶,¹¹⁻¹⁹. However, numerous atom vacancies anticipated in sensors that are expected to exhibit giant asymmetries may make it difficult to maintain stability under ambient conditions. Here, we report a piezoelectric sensor that exhibits supreme pressure-sensing performance, including a peak sensitivity up to 3.5×10⁶ kPa⁻¹ in the pressure range of 1-100 mPa and a detection limit of less than 1 mPa, superior to the current state-of-the-art pressure sensors. These properties are attributed to the high percentage of periodic atom vacancies in the two-dimensional Na₂Cl crystals formed within multilayered graphene oxide membrane in the sensor, which provides giant polarization with high stability. The sensor can even clearly detect the airflow fluctuations surrounding a flapping butterfly, which have long been the elusive tiny signals mentioned in the famous “butterfly effect”. The finding represents a step towards next-generation pressure sensors for various precision applications.