Biological signals generated during various biological processes are critically important for providing insight into the human physiological status. Recently, there have been many great efforts in developing flexible and stretchable sensing systems to provide biological signal monitoring platforms with intimate integration with biological surfaces. Here, this review summarizes the recent advances in flexible and stretchable sensing systems from the perspective of electronic system integration. A comprehensive general sensing system architecture is described, which consists of sensors, sensor interface circuits, memories, and digital processing units. The subsequent content focuses on the integration requirements and highlights some advanced progress for each component. Next, representative examples of flexible and stretchable sensing systems for electrophysiological, physical, and chemical information monitoring are introduced. This review concludes with an outlook on the remaining challenges and opportunities for future fully flexible or stretchable sensing systems.

Cephalotaxus oliveri is an endangered tertiary relict conifer endemic to China. The species survives in a wide range from west to east with heterogeneous climatic conditions. Precipitation and temperature are main restrictive factors for distribution of C. oliveri. In order to comprehend the mechanism of adaptive evolution to climate variation, we employed ISSR markers to detect adaptive evolution loci, to identify the association between variation in temperature and precipitation and adaptive loci, and to investigate the genetic structure for 22 C. oliveri natural populations. In total, 14 outlier loci were identified, of which five were associated with temperature and precipitation. Among outlier loci, linkage disequilibrium (LD) was high (42.86%), which also provided strong evidence for selection. In addition, C. oliveri possessed high genetic variation (93.31%) and population differentiation, which may provide raw material to evolution and accelerate local adaptation, respectively. Ecological niche modeling showed that global warming will cause a shift for populations of C. oliveri from south to north with a shrinkage of southern areas. Our results contribute to understand the potential response of conifers to climatic changes, and provide new insights for conifer resource management and conservation strategies.

Degradable electronics that dissolve or disintegrate in the environment after completing target functions are highly desirable due to great capabilities to eliminate the disposal, retrieval, and recycling of electronic waste worldwide. Constructing electronic systems on water‐soluble substrates via transfer printing technology has emerged as a promising approach toward this goal. However, the current approach suffers from low yields and thus hinders the complexity and scale of the obtained system in practical applications. Here, a wafer‐scale manufacturing process is proposed for degradable systems with high yields. As a demonstration, chips based on carbon nanotube thin films are 100% successfully transferred to water‐soluble substrates with an average device yield of 96.6%. Great uniformity is also obtained in the transferred thin‐film transistors (TFTs) and integrated circuits with a minimum standard deviation of 55 and 60 mV in the threshold voltage of TFTs and switching threshold voltage of inverters, respectively. System‐level demonstration of real‐time environmental monitoring is implemented in a simulated ecosystem together with a degradation demonstration under artificial rain. With its combined great performance, processing robustness, and high yields, this technology provides new opportunities for batch manufacturing of degradable electronics and next‐generation ecofriendly sensing platforms for the coming Internet of Things era.

High-speed flexible circuits are required in flexible systems to realize real-time information analysis or to construct wireless communication modules for emerging applications. Here, we present scaled carbon nanotube-based thin film transistors (CNT-TFTs) with channel lengths down to 450 nm on 2-μm-thick parylene substrates, achieving state-of-the-art performances of high on-state current (187.6 μA μm−1) and large transconductance (123.3 μS μm−1). Scaling behavior analyses reveal that the enhanced performance introduced by scaling is attributed to channel resistance reduction while the contact resistance (180 ± 50 kΩ per tube) remains unchanged, which is comparable to that achieved in devices on rigid substrates, indicating great potential in ultimate scaled flexible CNT-TFTs with high performance comparable to their counterparts on rigid substrates where contact resistance dominates the performance. Five-stage flexible ring oscillators are built to benchmark the speed of scaled devices, demonstrating a 281 ps stage delay at a low supply voltage of 2.6 V.

Corporate environmental responsibility, in response to the call for sustainable development, has become a critical ethical capital for companies to increase firm values and to obtain resources. However, this also gives rise to the concern of "greenwashing" that companies may selectively release environmental performance information to mislead the public and investors. Using the administrative environmental penalty data of all listed companies in China from 2017 to 2018, this research examines the corporate's greenwashing strategies. Our results show that greenwashing by listed companies in China is widespread, that only 13.6% environmental penalties have been disclosed by companies during our studied period. Companies choose to greenwash environmental performance mainly due to future demand for investment and financing, and companies with higher debt levels are found more likely to engage in greenwashing. Our findings suggest that it is not a rare practice for Chinese companies to risk their business ethics to pursue economic interests. It is necessary to enforce environmental information disclosure for listed companies in China and to increase their costs of unethical behaviors.