This PDF file contains the front matters associated with SPIE Proceedings Volume 12210, including the Title Page, Copyright information, Table of Contents and Conference Committee list.

With the net zero carbon emissions target by 2050, in the agricultural sector, it is essential to employ technologies to reduce the consumption of energy and resources while enhancing the yield of crops. Learning about how measurable signals can indicate the growth status of various plants will be beneficial for designing plant health monitoring systems (PHMSs) that can be used around the globe for the efficient growth of plants. In this work, we have designed and employed an array of gas sensors, acting as an electronic nose, to monitor the health status of lettuce being grown in a chamber by measuring the emission and consumption of various gases and volatile organic compounds (VOCs). While emission of ethylene is a strong indicator, we have found that accurate concentration measurements of CO2 and alcohols can also be used to assess the health status of the plant at its different stages of growth, particularly at the seedling and vegetative stages. ~20% change in the alcohol concentration and more than 2 folds increase in the equivalent CO2 level was observed when brown leaves started growing before the plant died. The results of the studies can help to design a simple PHMS that can help grow vegetables at a high yield with minimum supervision

Metalated phthalocyanines (MPcs) are a special class of organic semiconductors having unique chemical structures and properties. The material’s conjugated 18-π electron structure enables a strong fusion with carbon nano tubes (CNTs) which have a highly delocalized π electron structure. This strong binding between MPc and CNT facilitates the study of the material in an electrochemical cell. Here in this account, we report a novel method of identifying the selectivity and sensitivity trend of several MPcs with different metal cores through an electrochemical approach. Sensor electrode was prepared by drop casting the MPc solution on paper strips coated with CNT ink, and then tested in electrochemical cell in a 2-electrode fashion. The nature of the redox reactions between MPc and the VOC analytes (i.e., acetone, ethanol, isopropanol, and methanol) were studied through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. Four different metalated phthalocyanines (CoPc, CuPc, MgPc, and ZnPc) are studied here. Experimental results suggest large shift in conductivity in the CoPc sensor upon exposure to ethanol, MgPc sensor upon exposure to isopropanol, and ZnPc sensor upon exposure to acetone.

With the increasing interest in wearable electronics, still, building electronic circuits on fabrics is challenging. Among different approaches, fiber shape electrochemical transistors are potentially suitable for various applications, particularly for bioelectronics. Fiber-based devices are getting popular because of their low fabrication cost, lightweight, and mechanical flexibility without losing their properties as sensors and transistors. In this work, we have studied an organic electrochemical transistor made from two conductive threads with a gel electrolyte. The transistor was tested when it was exposed to an acidic solution which then showed a change in the drain current. The results from testing the conductive thread between the drain and source reviled the effect of the pH on the PEDOT:PSS coating used as the semiconducting material in the transistor design. The results are encouraging for the applications in new low-cost, flexible bioelectronics sensing devices.

Due to their synaptic functionality based on interacting electronic and ionic charge carriers, organic electrochemical transistors (OECTs) appeal as highly attractive candidates for a new generation of organic neuromorphic devices. Despite their acknowledged application potential, little is still known about the underlying physics and traditional transistor models fail to accurately describe the phenomena observed. This deficiency comes in part from the fact that such models are largely based on an electrostatic approach for metal-oxide-semiconductor field-effect transistors (MOSFETs), which is a very strong abstraction to the volumetric and complex processes in OECTs. On the other hand, material studies reveal the potential of an alternative approach, taking into account the electrochemical processes by means of thermodynamics and thus considering the OECTs intricacy. These two approaches oppose each other in explaining OECTs, neither of which can claim a comprehensive explanation of the transistor on its own so far. A unification of the two sides, on the other hand, could come much closer to a substantial explanation and provide a more accurate picture of reality. After giving a short overview of the most significant concepts of the two explanatory directions, a framework is presented that might come very close to this merger, as it accurately reproduces essential transfer properties of OECTs in terms of thermodynamics for the first time.

Cinchona officinalis L. is one of the most important and historically medicinal plants from which the antimalarial drug known as quinine is extracted. It is currently an endangered species. Thus, in vitro culture techniques are applied to propagate the species and to evaluate the effect of artificial light on the physiological development of C. Officinalis L. under controlled conditions. In that sense, the current study has determined the impact of blue led light on the enhancement of growth and number of shoots of Cinchona officinalis L. In vitro explants of C. Officinalis L were cultured on Murashige and Skoog (MS) medium and cultured under the white (control) and blue light-emitting diodes (LED) light. After eight weeks, growth and bud numbers were determined in C. officinalis L. Interestingly, blue light treatment increased the shoot length and bud numbers in comparison with the control. Incorporating blue light during in vitro propagation of C. Officinalis L can be a beneficial way to increase plant quality. Future perspectives could include the impact of blue light on the production of secondary metabolites, activities of antioxidant enzymes, and protein expression of in vitro-grown C. Officinalis L.