The structure and mechanism of the human visual system contain rich treasures, and surprising effects can be achieved by simulating the human visual system. In this article, starting from the human visual system, we compare and discuss the discrepancies between the human visual system and traditional machine vision systems. Given the wide variety and large volume of visual information, the use of non-von Neumann structured, flexible neuromorphic vision sensors can effectively compensate for the limitations of traditional machine vision systems based on the von Neumann architecture. Firstly, this article addresses the emulation of retinal functionality and provides an overview of the principles and circuit implementation methods of non-von Neumann computing architectures. Secondly, in terms of mimicking the retinal surface structure, this article introduces the fabrication approach for flexible sensor arrays. Finally, this article analyzes the challenges currently faced by non-von Neumann flexible neuromorphic vision sensors and offers a perspective on their future development.
The sole situation of semi-crystalline structure induced single performance remarkably limits the green cryogels in the application of soft devices due to uncontrolled freezing field. Here, a facile strategy for achieving multifunctionality of cryogels is proposed using total amorphization of polymer. Through precisely lowering the freezing point of precursor solutions with an antifreezing salt, the suppressed growth of ice is achieved, creating an unusually weak and homogenous aggregation of polymer chains upon freezing, thereby realizing the tunable amorphization of polymer and the coexistence of free and hydrogen bonding hydroxyl groups. Such multi-scale microstructures trigger the integrated properties of tissue-like ultrasoftness (Young’s modulus <10 kPa) yet stretchability, high transparency (~92%), self-adhesion, and instantaneous self-healing (<0.3 s) for cryogels, along with superior ionic-conductivity, antifreezing (−58 °C) and water-retention abilities, pushing the development of skin-like cryogel electronics. These concepts open an attractive branch for cryogels that adopt regulated crystallization behavior for on-demand functionalities.
The research on proximity sensing electronic skin has garnered significant attention. This electronic skin technology enables detection without physical contact and holds vast application prospects in areas such as human‐robot collaboration, human‐machine interfaces, and remote monitoring. Especially in the context of the spread of infectious diseases like COVID‐19, there is a pressing need for non‐contact detection to ensure safe and hygienic operations. This article comprehensively reviews the significant advancements in the field of proximity sensing electronic skin technology in recent years. It covers the principles, as well as single‐type proximity sensors with characteristics such as a large area, multifunctionality, strain, and self‐healing capabilities. Additionally, it delves into the research progress of dual‐type proximity sensors. Furthermore, the article places a special emphasis on the widespread applications of flexible proximity sensors in human‐robot collaboration, human‐machine interfaces, and remote monitoring, highlighting their importance and potential value across various domains. Finally, the paper provides insights into future advancements in flexible proximity sensor technology.
Electrohydrodynamic (EHD) printing is a cutting-edge micro/nano manufacturing technology for flexible substrates. Generally, EHD printing uses an electric field to drive droplet jet printing, which has characteristics of low cost, simple structure, and high precision. According to the research status of EHD printing at home and abroad, this article mainly focuses on the processing and applications of demanding devices by EHD printing, as well as the influence of associated-processing parameters, with regard to the breakthrough of different kinds of electronic inks developed in recent 5 years. Upon the understanding of the challenges and opportunities from the point of view of engineering applications, optimization strategies for ink selection are put forward for driving EHD printing in various fields of transistors, sensors, biomedicine, and electroluminescent devices.