Triboelectric sensor arrays (TSAs), particularly those with stretchability and multiple variables, hold immense potential for advancing human–machine interaction and personalized healthcare. However, existing fabrication methods often suffer from complex instrumentation, material limitations, and inefficiencies that hinder rapid prototyping. In this work, a low-cost and scalable one-step casting strategy is proposed for fabricating a stretchable TSA using Ecoflex and a conductive sponge electrode. A single-electrode triboelectric nanogenerator was systematically optimized in terms of surface morphology, electrode thickness, and Ecoflex thickness, achieving an output voltage of ~ 640 V, a short-circuit current of ~ 7.5 μA, and a peak power density of 2.82 W/m², with stable performance over 12,000 cycles. Notably, the device maintained functionality under 125% strain and exhibited enhanced output at 56.25% strain, demonstrating excellent mechanical stability and robustness. Scalable TSA configurations ranging from 2 × 2 to 4 × 4 pixels were developed for multifunctional sensing applications: a 2 × 2 TSA enabled light-emitting diode (LED) control and real-time visual positioning; a 4 × 4 TSA was used as a self-powered keyboard for numerical input; and a 3 × 3 TSA integrated with a LabVIEW interface allowed touchscreen-like motion tracking. For gait monitoring, a 2 × 2 TSA-integrated insole mapped plantar pressure and achieved 99.435% user identification accuracy using a lightweight one-dimensional convolutional neural network (1D-CNN). When extended to multi-gait sensing modes (slow/normal walking, slow running), a MobileNetV4 model with channel attention achieved 96.531% accuracy across 12 identity-activity combinations. This work demonstrates a versatile and accessible platform for scalable, self-powered stretchable electronics, with broad implications for wearable systems, soft robotics, and artificial intelligence (AI)-assisted healthcare.

The advancement of the information era has raised growing interest in triboelectric nanogenerators (TENGs) as environmentally friendly micropower sources. However, most developments to increase the power outputs of TENGs have focused on tribo-negative materials, with limited exploration of tribo-positive materials. This research addresses this gap by introducing poly(propylenemonothiocarbonate) (PPMNTC) as a tribo-positive material to enhance TENG performance. Density functional theory was utilized to investigate the triboelectric properties of PPMNTC and compare them with those of polyamide-6 (PA6), a common tribo-positive polymer for TENGs. Density functional theory analysis revealed that PPMNTC exhibits superior electron-donating capabilities due to the existence of high contents of thiol and methoxy groups. Kelvin probe force microscopy was used to confirm the markedly higher surface potential of PPMNTC compared to that of PA6. Meanwhile, cyclic voltammetry measurements revealed that PPMNTC also possesses a deeper highest occupied molecular orbital level than PA6. PPMNTC was utilized to fabricate TENGs paired with fluorinated ethylene propylene film. The 2 × 2 cm² TENG generated a maximum voltage of 1,450 V and an exceptional transferred charge density of 300 μC/m², 3- and 4-fold of those of the PA6/fluorinated ethylene propylene TENG, demonstrating the superior properties of PPMNTC as a tribo-positive material. This study drastically expands the material selection for TENGs, offering promising prospects for future applications.

Self-powered wireless sensing system is particularly suitable for applications in intelligent manufacturing, smart healthcare etc. as it does not require an external power source. Triboelectric nanogenerator (TENG) is an emerging energy harvester that can be used to power self-powered wireless sensors. The latest achievement in this area is the instantaneous self-powered wireless sensor, where the electric energy generated by the TENG is injected directly into the inductor-capacitor (LC) resonator to generate a decaying oscillating signal with encoded sensing information. However, the frequency is lower (typically < 5 MHz) and the signal transmission distance is short (< 3 m) limited by the near-field magnetic coupling, restricting its widespread applications. In this research, we propose a self-powered long-distance wireless sensing platform which utilizes a surface acoustic wave (SAW) resonator based radio-frequency oscillator to convert TENG energy into a high frequency signal with sensing information encoded. With this system, the sensing signal can be easily transmitted through the antenna for long distance. An optimized system is designed and conditional influences are fully investigated. Results show this self-powered wireless sensor system can perform wireless sensing for force, temperature and vibration at a distance up to 50 m.

Few-layer nanosheets (NSs) of hexagonal boron nitride (h-BN) and molybdenum disulfide (MoS₂) display notable piezoelectric properties. Yet, their integration into polymers typically yields non-piezoelectric composites due to NSs’ random distribution. We introduce a facile method for fabricating intrinsic piezoelectric composites incorporated with NSs without electric poling. Our innovative process aligns NSs within polyvinyl alcohol polymer, leveraging ice-water interfacial tension, water crystallization thrust, and directional cross-linking during freezing. The resulting PE composites exhibit a maximum piezoelectric coefficient of up to 25.5–28.4 pC N⁻¹, comparable to polyvinylidene difluoride (PVDF), with significant costefficiency, safety, and scalability advantages over conventional materials. Using this composite, we develop highly sensitive wearable pressure and strain sensors, and an ultrasound energy harvester. These sensors detect finger bending and differentiate between walking and running, while the harvester generates ~1.18 V/2.31 μA under 1 W cm⁻² ultrasound input underwater. This universal method offers a novel manufacturing technique for piezoelectric composites, demonstrating remarkable effectiveness in synthesizing intrinsic piezoelectric composites based on 2D materials. Moreover, its potential extends to applications in wearable electronics and energy harvesting, promising significant advancements in these fields.

Self-powered sensors are highly sought for wireless sensing applications in space exploration, industries, and environmental monitoring, etc. However, most current self-powered sensor technologies are based on the multiple energy conversion routine: energy collection, rectification, energy storage, and power management before it can be used for sensor systems, leading to exceptionally low energy utilization efficiency and very short periods of wireless sensing operation with majority of information lost. Here, we propose a triboelectric nanogenerator (TENG) based fully self-powered instantaneous and real-time wireless sensor system which does not contain electronic devices and microchips, but the passive components only. An innovative cylindrical capacitive-type liquid level sensor is also proposed and is then integrated into the wireless sensor system for monitoring liquid levels or identifying substance of the liquids. This sensor system can convert pulsed voltage output of the TENG into sinusoidal signal with a resonant frequency containing the sensing information and is transmitted to the receiver in distance in real-time. The maximum transmission distance of the sensor system could reach 1.5 m for a 10 cm diameter magnetic-core coil pair. The wireless sensor system exhibited excellent stability and excellent linearity with a sensitivity of 4.63 kHz/cm, and demonstrated its great application potential for the self-powered liquid level monitoring.