Wearable sensing technology is an essential link to future personalized medicine. However, to obtain a complete picture of human health, it is necessary but challenging to track multiple analytes inside the body simultaneously. Here, we present a wearable plasmonic-electronic sensor with “universal” molecular recognition ability. Flexible plasmonic metasurface with surface-enhanced Raman scattering (SERS)–activity is introduced as the fundamental sensing component in a wearable sensor since we solved the technical challenge of maintaining the plasmonic activities of their brittle nanostructures under various deformations. Together with a flexible electronic sweat extraction system, our sensor can noninvasively extract and “fingerprint” analytes inside the body based on their unique SERS spectra. As a proof-of-concept example, we successfully monitored the variation of trace-amounts drugs inside the body and obtained an individual’s drug metabolic profile. Our sensor bridges the existing gap in wearable sensing technology by providing a universal, sensitive molecular tracking means to assess human health.

The boom of plant phenotype highlights the need to measure the physiological characteristics of an individual plant. However, continuous real-time monitoring of a plant's internal physiological status remains challenging using traditional silicon-based sensor technology, due to the fundamental mismatch between rigid sensors and soft and curved plant surfaces. Here, the first flexible electronic sensing device is reported that can harmlessly cohabitate with the plant and continuously monitor its stem sap flow, a critical plant physiological characteristic for analyzing plant health, water consumption, and nutrient distribution. Due to a special design and the materials chosen, the realized plant-wearable sensor is thin, soft, lightweight, air/water/light-permeable, and shows excellent biocompatibility, therefore enabling the sap flow detection in a continuous and non-destructive manner. The sensor can serve as a noninvasive, high-throughput, low-cost toolbox, and holds excellent potentials in phenotyping. Furthermore, the real-time investigation on stem flow insides watermelon reveals a previously unknown day/night shift pattern of water allocation between fruit and its adjacent branch, which has not been reported before.

This article focuses on state-of-the-art technologies used in the research on materials, devices and processes to achieve high-performance QD-LEDs.

AbstractsQuantum dot light-emitting diodes (QD-LEDs) are considered as competitive candidate for next-generation displays or lightings. Recent advances in the synthesis of core/shell quantum dots (QDs) and tailoring procedures for achieving their high quantum yield have facilitated the emergence of high-performance QD-LEDs. Meanwhile, the charge-carrier dynamics in QD-LED devices, which constitutes the remaining core research area for further improvement of QD-LEDs, is, however, poorly understood yet. Here, we propose a charge transport model in which the charge-carrier dynamics in QD-LEDs are comprehensively described by computer simulations. The charge-carrier injection is modelled by the carrier-capturing process, while the effect of electric fields at their interfaces is considered. The simulated electro-optical characteristics of QD-LEDs, such as the luminance, current density and external quantum efficiency (EQE) curves with varying voltages, show excellent agreement with experiments. Therefore, our computational method proposed here provides a useful means for designing and optimising high-performance QD-LED devices.

In this paper, new strategies are proposed to design high-performance organic-inorganic hybrid perovskite (PVK)-based triboelectric nanogenerators (TENGs) via both chemical composition modulation and electric field-induced ion migration in the films. Both composition variation and ion migration under electric field are found to change the type of conductivity of the perovskite films, then modify their surface potentials and electron affinities. These are utilized to fabricate PVK-based TENGs in pairs with poly-tetrafluoroethylene (PTFE) or nylon films, respectively. Results show that PVK films are able to work as either a positive or a negative tribo-material depending on the tribo-material pair used; the optimal performances are obtained for PTFE/ PVK TENGs using a PVK film with a MAI/PbI 2 ratio of 2 and forward polarization, and for nylon/PVK TENGs using a PVK film with a MAI/PbI 2 ratio of 0.4 and reverse polarization, respectively. The maximum output voltage and peak power density of PTFE/PVK TENGs are about 979 V and 24 W m −2 , 2.5 and 6.5 times higher than those of TENGs with nonoptimal composition ratio or that are poorly polarized. This work provides a new material design method for high-performance TENGs and a novel polarization strategy for TENG performance enhancement.