Tactile sensors with visible light feedback functions, such as wearable displays and electronic skin and biomedical devices, are becoming increasingly important in various fields. However, existing methods cannot meet the application requirements for the tactile perception of intensity feedback and extended intersection due to their limited light‐mapping performance and insufficient portability. Herein, a freely constructible self‐powered visual tactile sensor is proposed, which consists of a high‐output triboelectric nanogenerator (TENG) and a visual light source. The transferred charge of the TENG is enhanced to 746 nC by the structural design of the triboelectric material and device, which can easily drive the light source to generate a light signal with a brightness of 9.8 cd m−2. Notably, the application of the TENG enables to realization visual sensing of the palm‐grasp state and strength feedback without an external power supply. This visual feedback and power‐free tactile sensors are expected to have potential application in the field of artificial intelligence as a new interactive medium for smart protective clothing and robotics.

Wearable Triboelectric Visual Sensors for Tactile Perception

Cellulose template-based triboelectric nanogenerators for self-powered sensing at high humidity

The rapid rise of triboelectric nanogenerators (TENGs), which are emerging energy conversion devices in advanced electronics and wearable sensing systems, has elevated the interest in high‐performance and multifunctional triboelectric materials. Among them, cellulosic materials, affording high efficiency, biodegradability, and customizability, are becoming a new front‐runner. The inherently low dielectric constant limits the increase in the surface charge density. However, owing to its unique structure and excellent processability, cellulose shows great potential for dielectric modulation, providing a strong impetus for its advanced applications in the era of Internet of Things and artificial intelligence. This review aims to provide comprehensive insights into the fabrication of dielectric‐enhanced cellulosic triboelectric materials via dielectric modulation. The exceptional advantages and research progress in cellulosic materials are highlighted. The effects of the dielectric constant, polarization, and percolation threshold on the charge density are systematically investigated, providing a theoretical basis for cellulose dielectric modulation. Typical dielectric characterization methods are introduced, and their technical characteristics are analyzed. Furthermore, the performance enhancements of cellulosic triboelectric materials endowed by dielectric modulation, including more efficient energy harvesting, high‐performance wearable electronics, and impedance matching via material strategies, are introduced. Finally, the challenges and future opportunities for cellulose dielectric modulation are summarized.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/advs.202206243

Fabrication of Advanced Cellulosic Triboelectric Materials via Dielectric Modulation

Cellulosic triboelectric materials for stable energy harvesting from hot and humid conditions

Nanocellulosic triboelectric materials with micro-mountain arrays for moisture-resisting wearable sensors

With the vigorous development of the Internet of Things and artificial intelligence, the active sensing system based on triboelectric nanogenerators plays an excellent performance potential and application value as a pioneering technology for smart manufacturing. Nevertheless, achieving material innovation to strike a good balance between active sensing systems and environmental friendliness remains a difficult task. As the most abundant biopolymer on earth, the sustainability potential and excellent performance of cellulose are of great importance for the development of smart sensing systems. This review intends to provide a new perspective on the sustainability of smart active sensing systems to design and fabricate cellulosic triboelectric materials for self‐powered sensing systems. Herein, the structure and advantageous properties of cellulosic triboelectric materials are briefly described. Furthermore, the structure–property–application relationship of the materials is addressed from the perspective of material design and structure optimization. Next, the latest applications of cellulose triboelectric materials are comprehensively described in smart sensing fields such as environmental monitoring, smart home, smart medical, human–machine interaction, and the Internet of everything. Lastly, the current challenges and future developments of cellulose triboelectric materials for smart sensor systems are presented.

Zhiting Wei

Papers

Sustainable Triboelectric Materials for Smart Active Sensing Systems

Fabrication of Advanced Cellulosic Triboelectric Materials via Dielectric Modulation