To solve the problems of preparation process,flexibility,and flexibility of friction electric fibers,super-elastic triboelectric fibers were prepared by using an extrusion-filling method.The liquid metal EGaIn and thermoplastic elastomer material were used as the conductive electrode and the fiber sleeve,respectively.The fiber could sustain strains up to 2200%and exhibited high electrical outputs.By using a 5 cm long fiber as the medium,the fiber can provide an unsaturated average open circuit voltage of 7 V when in contact with paper;and the instantaneous power density of 1.6 μW/m was obtained with an external load resistance of 200 MΩ.Weaning the fiber into an 8 cm×8 cm textile,the max electrical outputs were 120 V,280 nA,28 nC.Results show that the extrusion-filling technology is an effective way to develop stretchable triboelectric fibers.The super-elastic fibers in this work have the potential for multi-functional wearable smart textiles applications.

Flexible and wearable textile -based triboelectric nanogenerators (TENGs) have attracted extensive attention in wearable electronics owing to their ability to convert waste mechanical energy from human motion into electrical energy. However, the performances of TENGs are lower than those of planar/film configurations due to the complex fiber fabrications and limited mechanical freedom. In this work, we demonstrate an extrusion method combined with thermal drawing (ETD method) for continuous and scalable triboelectric fiber fabrication, providing longitudinal uniform fibers for hundreds of kilometers. Based on the ETD method, super -elastic microstructured triboelectric fibers (SMTFs) were fabricated, consisting of hollow elastomeric and liquid metal cores (EGaIn). The SMTFs showed excellent superelasticity with clear and uniform microstructures. The fibers could withstand strain up to 1800% and exhibited excellent electrical output performance. Utilizing a single fiber as the medium for triboelectric energy collection, the average open circuit voltage and instantaneous power density are respectively up to 210 V/m and 21 mu W/m with a 40 M omega external load resistance. The SMTFs could also be woven into deformable textiles with high electrical outputs up to 160 V, 10 mu A, and 50 nC. In addition, the SMTFs-based textiles were further demonstrated as completely soft and stretchable components for self -powered sensing in smart home applications.

The layered van der Waals materials γ-InSe showed great potential in integrated photonic devices and microlasers due to the high electron mobility, wide tunable direct bandgap, and high lattice compressibility. However, γ-InSe crystal has weak stability and dissociation tendency in ambient conditions, which hampers its applications. Herein, we proposed a novel method for single-crystal InSe. By thermal stretching combined with photothermal processing, ultralong and layered single-crystal InSe fibers were obtained. The InSe fiber core was effectively restrained and protected, improving the mechanical properties and stability of the device. Moreover, by using a 532 nm nanosecond pulse laser as the pump source, the WGM microlaser operating at 1107.33 nm was obtained. This work provides a convenient approach for van der Waals materials preparation and paves the pathways for the development of light sources for layered van der Waals materials.

Indium selenide (InSe) crystal, as an emerging Van der Waals semiconductor, showed great potential in optical and optoelectronic devices due to its remarkable electron mobility, flexible direct bandgap, and photoresponsivity. Especially, the bulk single-crystalline InSe shows superplastic deformability with the aid of the interlayer gliding and cross-layer dislocation slip. The extraordinary mechanical behavior brings significant opportunities and possibilities to pressure-modulated optical devices, which, however, have not been explored sufficiently. Additionally, InSe crystals are challenged in the rapid large-scale preparation and reproduction due to limitations, such as phase heterogeneity, dissociation risks, and chemical instability. Herein, we proposed a fiber drawing technique to create single-crystalline InSe by the molten core drawing method combined with CO2 laser-induced recrystallization. The fabricated InSe fiber, spanning several meters in length, shows a uniform and directional single-crystalline InSe core encased within a 450 mu m thick protective borosilicate glass cladding. The inherent core-cladding configuration of the InSe fibers not only provides robust protection to the InSe crystals but also seamlessly creates a whispering-gallery-mode microcavity. Utilizing a 532 nm nanosecond pulsed laser as a pump, a tunable lasing from 1076.2 to 1111.8 nm was achieved, dictated by the controlled pressure within the InSe fiber. We present a simple and effective method for single-crystalline InSe fabrication and first achieve a pressure-modulated laser in a near-infrared band based on InSe fiber, heralding an advancement for the scalable, efficient generation of tunable lasers. Single-crystalline indium selenide fibers by laser-induced recrystallization and their tunable whispering-gallery-mode lasing by pressure-modulating. image

Due to the strong light–matter interactions, van der Waals semiconducting materials have shown their great potential in the development of high-performance photodetectors. However, the van der Waals semiconducting devices via conventional growth method often introduce defects or are in the form of isolated flakes, which hinders the optoelectronics from widespread applications. In this paper, van der Waals semiconductor indium selenide (InSe) fibers for photodetection were developed based on thermal drawing. Meters level length of InSe fibers have been fabricated through thermal drawing, and the problem of easy cracking of InSe is solved. The InSe fibers have high crystallinity, and it is found that the cleavage planes have a preferential orientation. The InSe fibers show a high-speed response to modulated 639 nm laser irradiation with up to 10 kHz repetition rate. In addition, the photoelectric response of the fibers were further improved through annealing by CO2 laser.