Multimodal Plant Healthcare Flexible Sensor System

Abstract

The rising global human population and increased environmental stresses require a higher plant productivity while balancing the ecosystem using advanced nanoelectronic technologies. Although multifunctional wearable devices have played distinct roles in human healthcare monitoring and disease diagnosis, probing potential physiological health issues in plants poses a formidable challenge due to their biological complexity. Herein an integrated multimodal flexible sensor system is proposed for plant growth management using stacked ZnIn2S4(ZIS) nanosheets as the kernel sensing media. The proposed ZIS-based flexible sensor can not only perceive light illumination at a fast response (∼4 ms) but also monitor the humidity with a perdurable steady performance that has yet to be reported elsewhere. First-principles calculations reveal that the tunneling effect dominates the current model associated with humidity response. This finding guides the investigation on the plant stomatal functions by measuring plant transpiration. Significantly, dehydration conditions are visually recorded during a monitoring period (>15 days). This work may contribute to plant–machine biointerfaces to precisely manage plant health status and judiciously utilize limited resources.

A Wearable Body Condition Sensor System with Wireless Feedback Alarm Functions

“…This is because water molecules reduce the bandgaps of ZIS nanomaterials. [ 51 ] When the ZIS film thickness is ≈770 nm, the resistance of the humidity sensor decreases by ≈40% with a rapid recovery time of less than 10 s after retracting 100 µL water. Increasing the ZIS film thickness improves the resistance change up to 64%.…”

A Morphable Ionic Electrode Based on Thermogel for Non‐Invasive Hairy Plant Electrophysiology

“…Future work will be developing electrodes that can accommodate plant growth for longer periods of monitoring and fast-growing seedlings. Our work sets the scene for future device development toward smart plant monitoring and modulation, which will find wide applications in environmental sensing, [7] crop health monitoring, [11] plant physiology regulation and modification, [9,11,[46][47][48] and augmented human-plant interaction. [8,10] Using hairy plants as a model system, we proved the efficacy of morphable materials that involve liquid-to-solid (or semisolid) transition in bridging textured biological tissues.…”

Wireless and Flexible Skin Moisture and Temperature Sensor Sheets toward the Study of Thermoregulator Center

“…As explained for most humidity sensors, the sensing mechanism of the ZIS humidity sensor is also based on a proton‐hopping process between H 3 O + ions and water molecules, in which the highest energy occupied molecular orbital–lowest energy unoccupied molecular orbital (HOMO–LUMO) gap of this semiconductor material is reduced, leading to an enhanced current level (Figure 2b). [ 15 ] The surface morphology of the ZIS nanosheets and LIG electrodes are shown in Figure 2c,d and Figure S1 in the Supporting Information, respectively. The high porosity of the graphene electrodes provides sufficient interspace for water adsorption and desorption through the ZIS nanosheet surface, resulting in better and stable humidity response, as we have previously reported.…”

“…In particular, this study aims to continuously monitor the finger‐skin temperature and moisture variation under a cold stimulus and during running using the proposed integrated wireless flexible sensor system. Both the ZnIn 2 S 4 humidity sensor [ 15,16 ] and CNT/SnO 2 temperature sensor [ 17 ] feature commendable stability, which guarantee good performance for long‐time monitoring. The ZIS humidity sensor is fabricated with porous graphene electrodes, which are produced by laser scanning process.…”