Nanoimprint assisted free standing porous vanadium oxide nanosheet based ammonia sensor

Artificial intelligence in healthcare sector endures a largest share in non-invasive and point-of-care disease diagnosis by interfacing human behaviour through wearable pathway. In a view to develop sensing element for wearables, the concept of free standing poly-1-lactic acid (PLLA)/V2O5 nanosheets using sacrificial layer - (poly vinyl alcohol- PVA)method has been proposed in this work and the studies on ammonia (NH3) sensing has been briefly discussed. In a view to enhance the sensing performance of vanadium pentoxide (V2O5) film, surface modified PLLA substrates using nanoimprint lithography (NIL) have been implemented. The V+5 stoichiometry of the free standing PLLA/V2O5 films were confirmed using x-ray photoelectron spectroscopy (XPS). From field emission scanning electron microscopy (FE-SEM), it was observed that the patterned structure of about similar to 250 nm diameter was uniformly distributed on the surface of PLLA/V2O5 film. The chemiresistive sensing studies proved that the sensor response of V2O5 films on patterned PLLA substrate exhibited enhanced response about similar to 17 towards 75 ppm than the V2O5 film on unpatterned PLLA substrate. We believe that this strategy of patterned free standing PLLA/V2O5 nanosheets will help in fabricating the wearable sensors with better sensing performance.

Automated summary

This study proposed a new method for sensing elements in wearables, using standalone PLLA/V2O5 nanosheets to improve ammonia sensing response. Surface modification of PLLA substrates using nanoimprint lithography was implemented to enhance sensing performance.