Field Deployment of A Nanogap Gas Sensor For Crop Damage Detection

This paper reports the first in-field detection of actual hexanal from the damaged sorghums using the field-deployed nano-gap gas sensor. The previously developed nano-gap gas sensor was fully integrated with electronics and wireless communication units into a portable prototype (10×10× 7 c m
³
). The field deployed gas sensor prototype successfully detected the 'scream‘ from the mechanically damaged sorghums by detecting a particular gas molecule, hexanal, released after the time point of 3.5 hours since the start of leaf cutting. The sensor prototype was pre-programmed to detect >100 ppm concentrations of hexanal in ambient air. After 1.5 hours since the cutting was stopped, the sensor prototype successfully recovered. The sorghum field testing conditions included a temperature (25~120 °C) and humidity (≤70%RH). The detection demonstration clearly indicated that (1) a prototype successfully captured actual hexanal released from the damaged sorghums real-time and that (2) it was feasible to monitor a mechanically-stressed status of sorghums by gas monitoring.