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A type of strain sensor with high tolerable strain based on a ZnO nanowires/polystyrene nanofibers hybrid structure on a polydimethylsiloxane film is reported. The novel strain sensor can measure and withstand high strain and demonstrates good performance on rapid human-motion measurements. In addition, the device could be driven by solar cells. The results indicate that the device has potential applications as an outdoor sensor system.

The last decade has witnessed significant advances in energy harvesting technologies as a possible alternative to provide a continuous power supply for small, low-power devices in applications, such as wireless sensing, data transmission, actuation, and medical implants. Piezoelectric energy harvesting (PEH) has been a salient topic in the literature and has attracted widespread attention from researchers due to its advantages of simple architecture, high power density, and good scalability. This paper presents a comprehensive review on the state-of-the-art of piezoelectric energy harvesting. Various key aspects to improve the overall performance of a PEH device are discussed, including basic fundamentals and configurations, materials and fabrication, performance enhancement mechanisms, applications, and future outlooks.

Versatile and low-cost manufacturing processes/materials are essential for the development of paper electronics. Here, a direct-write laser patterning process is developed to make conductive molybdenum carbide-graphene (MCG) composites directly on paper substrates. The hierarchically porous MCG structures are converted from fibrous paper soaked with the gelatin-mediated inks containing molybdenum ions. The resulting Mo3 C2 and graphene composites are mechanically stable and electrochemically active for various potential applications, such as electrochemical ion detectors and gas sensors, energy harvesters, and supercapacitors. Experimentally, the electrical conductivity of the composite is resilient to mechanical deformation with less than 5% degradation after 750 cycles of 180° repeated folding tests. As such, the direct laser conversion of MCGs on papers can be applicable for paper-based electronics, including the 3D origami folding structures.

Self-powered human-interactive but invisible electronics have many applications in anti-theft and anti-fake systems for human society. In this work, for the first time, we demonstrate a transparent paper-based, self-powered, and human-interactive flexible system. The system is based on an electrostatic induction mechanism with no extra power system appended. The self-powered, transparent paper device can be used for a transparent paper-based art anti-theft system in museums or for a smart mapping anti-fake system in precious packaging and documents, by virtue of the advantages of adding/removing freely, having no impairment on the appearance of the protected objects, and being easily mass manufactured. This initial study bridges the transparent nanopaper with a self-powered and human-interactive electronic system, paving the way for the development of smart transparent paper electronics.

A paper-based active tactile sensor -array (PATSA) with a dynamic sensitivity of 0.35 V N(-1) is demonstrated. The pixel position of the PATSA can be routed by analyzing the real-time recording voltages in the pressing process. The PATSA performance, which remains functional when removing partial areas, reveals that the device has a potential application to customized electronic skins.

Fiber-based generator (FBG) and active fiber-based strain sensor (AFSS) were fabricated via commodity cotton threads and simple ideas. These devices can be applied in wearable electronics and human healthy monitoring.

An electret material with high charge storage ability is the key factor for fabricating high performance electret generator for wearable electronics and self-powered sensor systems. This work presents a new sandwiched composite fluorocarbon (SCF) film, which stores more residual charges compared to traditional electret materials such as dense fluorinated ethylene propylene or fibrous polytetrafluoroethylene films with the same thickness. Electret generator based on the SCF film shows a largest peak power density of ≈31.4 μW cm−2 with load resistance of 40 MΩ. Moreover, the application of the electret generator for a self-powered human breathing sensor is also demonstrated. This work offers a new strategy to enhance the output of the electret generators.

Paper-based functional electronic devices endow a new era of applications in radio-frequency identification (RFID), sensors, transistors and microelectromechanical systems (MEMS). As an important component for building an all paper-based system that can work independently and sustainably, a paper-based power source is indispensable. In this study, we demonstrated a paper-based nanogenerator (pNG) that can convert tiny-scale mechanical energy into electricity. The pNG relies on an electrostatic effect, and the electrostatic charges on the paper were generated by the corona method. The instantaneous output power density of a single-layered pNG reached ∼90.6 μW cm−2 at a voltage of 110 V, and this instantaneously illuminated 70 LEDs. In addition, by sticking the pNG to a movable object, such as the page of a book, the power harvested from the mechanical action of turning the page can drive an LED, which presents its outstanding potential in building paper-based, self-powered systems and as active sensors.

Nowdays, the study of measurement of the biological field focuses on the research of improving surface plasmon resonance (SPR) in the fields of integration and detection sensitivity. We designed a kind of grating connected surface plasmon resonance sensor. Theoretically, we analyzed the wave vector and the effective refractive index relations with the diffraction grating structure. Then we obtained the nanoparticles enhancement SPR structure with a resolution 10 times higher than that of traditional SPR sensors. Also, we used the finite-difference time-domain (FDTD) analysis and simulation which showed that it was obvious with coupling effect by the nanoparticles enhancement SPR structure that the reflectance spectral bandwidth results validated the structure significantly which improved the sensitivity. Experimental results showed that the dynamic response of the designed sensor reached 10−6 RIU (refractive index unit). This study has the certain significance to long-distance and special sensing applications.