The Fabrication And Performance Optimization Of In-Situ And Non-Destructive Sensing Devices Based On Self-Powered For Plant Water Information

Water plays a crucial role in the normal growth and development of plants.Water stress not only affects the normal physiological activities of plants,but also causes economic losses.Therefore,visualization and real-time detection of plant water information is needed in actual production to avoid the occurrence of water stress,which can not only ensure the normal growth and development of plants,but also save agricultural water.However,the commonly used methods for detecting plant water information currently have issues such as expensive equipment,susceptibility to damage to plant leaves,and the need to frequently replace power supplies.Based on this,this article introduces a low-cost and simple self-powered flexible moisture information sensing device and constructed a self-powered plant water information in-situ non-destructive sensing system for visual detection of plant moisture information.The specific research contents and results are as follows:(1)A simple drop-coating process was used to construct graphene oxide(GO)functional layer films with different concentration gradients to prepare a GO-based self-powered flexible moisture sensing device.The effects of device area and film thickness on the device output performance are investigated and the stability of the device is analyzed.The experimental results show that the device area is positively correlated with the current output of the device,and within a certain range with the voltage output of the device,the film thickness is positively correlated with the response/recovery time of the device,and the electrical output performance of the device can be maximized by optimizing the film thickness.Taking into account the electrical output characteristics and moisture sensing characteristics of the device,the optimal process is selected to prepare a self-powered flexible moisture sensing device with a maximum open-circuit voltage of 800 m V,a short-circuit current of 1.6 μA,a sensitivity of 35.8 m V/%RH in high humidity environments,and good device stability.(2)To further optimize the moisture sensing capability of the device under a low humidity environment,a self-powered flexible moisture sensing device is prepared using GO and polyvinyl alcohol/lithium chloride(PVA/Li Cl)composite films.The effects of the device’s positive and negative electrode types and different co-mixing volume ratios of PVA/Li Cl on the output performance of the device are investigated,and the stability of the device is also studied.The experimental results indicate that the stronger the activity of the positive and negative electrode types,the better the electrical output performance of the device.Due to the strong water absorption of Li Cl,the voltage output and current output of the device are significantly enhanced at lower relative humidity environments.Considering the electrical output characteristics and moisture response characteristics of the device,indium tin oxide(ITO)and zinc metal sheets are selected as positive and negative electrodes,and PVA and Li Cl solutions are co-mixed in a 2:1 volume to prepare a self-powered flexible moisture sensing device.The device has a maximum open-circuit voltage of 1.1 V and a short-circuit current of 50 μA.It can achieve moisture detection in a wide range of relative humidity(20%–90%),with a sensitivity of 9 m V/%RH in low-humidity environments.(3)Based on the above research,through integrated circuit design and software design,the self-powered flexible moisture sensing device based on PVA/Li Cl film is integrated with hardware and software systems to construct a self-powered in-situ non-destructive sensing system for plant moisture information.The sensing performance and power supply performance of the self-powered flexible moisture sensing device are tested in the experiment.Subsequently,the self-powered moisture sensing system is used to detect the transpiration of plant leaves using the water vapor released by plant transpiration as an indicator of plant moisture information,realizing the in-situ and non-destructive real-time visual detection of plant moisture information.