Hang Guo

All-fabric-based wearable self-charging power cloth

We present an all-fabric-based self-charging power cloth (SCPC), which integrates a fabric-based single-electrode triboelectric generator (STEG) and a flexible supercapacitor. To effectively scavenge mechanical energy from the human motion, the STEG could be directly woven among the cloth, exhibiting excellent output capability. Meanwhile, taking advantage of fabric structures with a large surface-area and carbon nanotubes with high conductivity, the wearable supercapacitor exhibits high areal capacitance (16.76 mF/cm2) and stable cycling performance. With the fabric configuration and the aim of simultaneously collecting body motion energy by STEG and storing in supercapacitors, such SCPC could be easily integrated with textiles and charged to nearly 100u2009mV during the running motion within 6u2009min, showing great potential in self-powered wearable electronics and smart cloths.

Waterproof and stretchable triboelectric nanogenerator for biomechanical energy harvesting and self-powered sensing

We introduce a waterproof and stretchable triboelectric nanogenerator (TENG) that can be attached on the human body, such as fingers and the wrist, to harvest mechanical energy from body movement. The whole device is composed of stretchable material, making it able to endure diverse mechanical deformations and scavenge energy from them. Under gentle mechanical motions of pressing, stretching and bending, the device with an effective area of 1u2009 ×u20092u2009cm2 can generate the peak-to-peak output current of 257.5u2009nA, 50.2u2009nA, and 33.5u2009nA, respectively. Besides, the TENG is tightly encapsulated, enabling it to avoid the influence of the external environment like humidity changes and harvest energy under water. Particularly, owing to the thin and soft properties of the encapsulation film, the device can respond to weak vibrations like the wrist pulse and act as a self-powered pulse sensor, which broadens its application prospects in the field of wearable energy harvesting devices and self-powered sensing systems.

Microsphere‐Assisted Robust Epidermal Strain Gauge for Static and Dynamic Gesture Recognition

A novel and robust epidermal strain gauge by using 3D microsphere arrays to immobilize, connect, and protect a multiwalled carbon nanotubes (MWNTs) pathway is presented. During the solvent deposition process, MWNTs sedimentate, self-assemble, and wrap onto surface of polystyrene (PS) microspheres to construct conductive networks, which further obtain excellent stretchability of 100% by combining with commercially used elastomer. Benefiting from its 3D conductive pathway defined by microspheres, immobilized MWNT (I-MWNT) network can be directly used in practical occasions without further packaging and is proved by tape tests to be capable of defend mechanical damage effectively from external environment. By parameter optimization, the strain sensor with 3 µm PS spheres obtains stable resistive responses for more than 1000 times, and maintains its gauge factor (GF) of 1.35. This thin-film conductive membrane built by this effective construction method can be easily attached onto fingers of both robot and human, and is demonstrated in sensitive epidermal strain sensing and recognizing different hand gestures effectively, in static and dynamic modes, respectively.

Fabric-based self-powered noncontact smart gloves for gesture recognition

Fiber-based wearable electronics is a promising field primarily due to its capability of including multiple physical quantities for sensing. This paper presents a pair of fiber-based self-powered noncontact smart gloves with the unique function of recognizing a wide range of gestures without contact between fingertips and the palm. The one-dimensional noncontact localizing method has two working modes to distinguish the coordinate parallel or perpendicular to the direction of motions, with resolutions of 0.76xa0mm and 0.36 mm, respectively. Adopting a novel noncontact sensing mechanism based on electrostatic induction and triboelectric effects, such smart gloves outcompete other approaches relying on integrating contact sensing units and attaching strain or pressure sensors on human skins. It further solves the problem of electrode number reduction and energy supply, as well as improves user interaction experience. In addition, accommodation of flexible electrode configurations and gesture recognitions is innovatively proposed to enhance signal-noise ratio and reduce electrode numbers. The smart gloves consist of an electrified layer made of wool yarn and polydimethylsiloxane (PDMS) coated wool yarn, and an effective sensing layer on the palm, where electrodes made of carbon nanotubes (CNT) coated cotton fabric are sewn. With eminent characteristics such as flexibility, compatibility with human skin and less number of electrodes, these smart gloves provide excellent sensing ability and interaction experience in gesture recognition.