Printed bioinspired piezoelectric nano-hair for ultrahigh sensitive airflow detection

Micro/nanoscale hairs found in living organisms combine many inspiring properties such as miniaturization, low power consumption, adaptability, and the sensing of signals. Mimicking these excellent biological hairs provided an effective way to develop advanced artificial sensing sensors. Here, a printed bioinspired piezoelectric nano-hair with ultra-high sensitivity was developed for airflow detection. A novel nanoscale electrohydrodynamic jet 3D printing method was developed to fabricate PZT nano-hair with controllability, fast, and inexpensive characteristics. Various PZT nano-hairs down to the scale of 200 nm with high aspect ratio features of 523 were directly printed. Herein, the printed PZT nano-hair exhibited pure perovskite structures, excellent mechanical properties, and a high piezoelectric coefficient. This bioinspired PZT hair sensor demonstrated that the novel printed PZT hair airflow sensor showed ultra-high detection sensitivity to low-speed airflow (0.02 m s−1). This novel nanoprinting strategy and the printed PZT nano-hair indicate the development of functional nanostructures inaccessible by traditional manufacturing methods.