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Thermoelectric (TE) fibers have excellent potential for multimodal sensor, which can detect mechanical and thermal stimuli, used in advanced wearable electronics for personalized healthcare system. However, previously reported TE fibers have limitations for use in wearable multimodal sensors due to the following reasons: 1) TE fibers composed of carbon or organic materials have low TE performance to detect thermal variations effectively; 2) TE fibers composed of rigid inorganic materials are not stretchable, limiting their ability to detect mechanical deformation. Herein, the first stretchable TE fiber‐based multimodal sensor is developed using copper(I) iodide (CuI), an inorganic TE material, through a novel fabrication method. The dense CuI nanoparticle networks embedded in the fiber allow the sensor to achieve excellent stretchability (maximum tensile strain of ≈835%) and superior TE performance (Seebeck coefficient of ≈203.6 µV K−1) simultaneously. The sensor exhibits remarkable performances in strain sensing (gauge factor of ≈3.89 with tensile strain range of ≈200%) and pressure sensing (pressure resolution of ≈250 Pa with pressure range of ≈84 kPa). Additionally, the sensor enables independent and simultaneous temperature change, tensile strain, and pressure sensing by measuring distinct parameters. It is seamlessly integrated into a smart glove, demonstrating its practical application in wearable technology. [ABSTRACT FROM AUTHOR]

As the field of wearable electronics continues to expand, the integration of inorganic thermoelectric (TE) materials into fabrics has emerged as a promising development due to their excellent TE properties. However, conventional thermal methods for fabricating TE fabrics are unsuitable for wearable applications because of their high temperatures, resulting in rigid TE materials. Herein, a nonthermally fabricated silver selenide (Ag2Se) TE fabric is developed that can be effectively integrated into wearable applications. Ag2Se nanoparticles are densely formed within the fabric through a simple in situ chemical reduction process, resulting in remarkable electrical stability even after 10 000 cycles of mechanical deformation, such as stretching and compression. Notably, the fabricated Ag2Se TE fabric exhibits superior stretchability, stretching ≈1.36 times more than the thermally treated Ag2Se TE fabrics, while retaining its excellent electrical conductivity. Moreover, the TE unit exhibits 9.80 μW m−1 K−2 power factor, 134.45 S cm−1 electrical conductivity, and −26.98 μV K−1 Seebeck coefficient at 370 K. A haptic sensing glove based on the Ag2Se TE fabric as a sensor for detecting potential hazards is demonstrated. The glove effectively distinguishes between simple touch, physical pain, and high‐temperature hazards, ensuring user safety and prompt response. [ABSTRACT FROM AUTHOR]

Fiber‐based electronics are essential components for human‐friendly wearable devices due to their flexibility, stretchability, and wearing comfort. Many thermoelectric (TE) fabrics are investigated with diverse materials and manufacturing methods to meet these potential demands. Despite such advancements, applying inorganic TE materials to stretchable platforms remains challenging, constraining their broad adoption in wearable electronics. Herein, a multi‐functional and stretchable bismuth telluride (Bi2Te3) TE fabric is fabricated by in situ reduction to optimize the formation of Bi2Te3 nanoparticles (NPs) inside and outside of cotton fabric. Due to the high durability of Bi2Te3 NP networks, the Bi2Te3 TE fabric exhibits excellent electrical reliability under 10,000 cycles of both stretching and compression. Interestingly, intrinsic negative piezoresistance of Bi2Te3 NPs under lateral strain is found, which is caused by the band gap change. Furthermore, the TE unit achieves a power factor of 25.77 µWm−1K−2 with electrical conductivity of 36.7 Scm−1 and a Seebeck coefficient of −83.79 µVK−1 at room temperature. The Bi2Te3 TE fabric is applied to a system that can detect both normal pressure and temperature difference. Balance weight and a finger put on top of the 3 × 3 Bi2Te3 fabric assembly are differentiated through the sensing system in real time. [ABSTRACT FROM AUTHOR]