Fig. 7: Interactions of the PBJT sensory units/arrays with live/not-live objects.

a Schematic of wearables and interactions of the device with the environment and humans in sensing applications. Usage of piezotronic n-p-n sensing units for breath detection from the (b) mouth, where the sensory unit is mounted on a mask, and (c) nose, where the sensory unit is firmly attached to a portion of the upper lips. Pulse recording of a 35-year-old male from the (d) wrist and (e) neck, and (f) a 2\(\times\)2 array of the PBJT sensor fabricated on a PET substrate, with another supporting layer of PET is placed on top. The array consists of 4 similar pixels in 2 cm\(\times\)2 cm in size. g Photograph of the fabricated array. h Landing and taking off states of a particular live butterfly (lxias pyrene) is recorded utilizing an oscilloscope for scanning each row and column. i Path detection of a frog toy moving over the sensor array moving with a frequency of 5–10 Hz. j Pressure exerted on a unique pixel in an array by gentile, moderate, and high-pressure touch ranging between 4.5 kPa and 10 kPa for a gentle touch by an index finger