Publications

Inspired by endogenous physiological electric fields in humans, electricity has been widely used as an accessible source of physical stimulation to help treat diseases, including cancer therapy. Electricity can not only be used as a weapon to directly kill cancer cells but also be used as a “switch” to control the anticancer drug delivery systems (DDSs), enabling on‐demand drug release at the lesion sites. Recently, the antitumor electrotherapy based on the induction of tumor cell apoptosis by highly toxic reactive oxygen species (ROS) has been developed. Many studies have proved that the electrical stimulation can mobilize the body's immune system to kill tumors through different mechanisms. When the single electrical therapy is not effective for the treatment of advanced tumors, the integration with immunotherapy is considered as “life‐saving straw.” Moreover, with the growing need for convenient, personalized, and telehealth care and treatment, the emerging nanotechnologies such as self‐powered triboelectric nanogenerators (TENGs) are integrated with electrotherapy. This review comprehensively summarizes these developments from clinic applications to new emerging strategies and proposes future challenges and opportunities in this field.

A technique has been developed to transform a Si-Ge thin film into Si-Ge oxide nanowires with the assistance of Au particles through a three-step annealing process. A honeycomb network of Au colloidal nanoparticles was self-assembled; 400°C annealing removes the surface surfactant; 800°C annealing forms hexagonally self-assembled Au particles on the thin-film surface; finally, a 1075°C annealing results in the growth of oxide nanowires on the surfaces of Au particles. Synthesized nanowires have an emission peak at 3.3 eV. This technique is useful for growing silicon oxide nanowires with a tunable amount of Ge doping.

Abstract Functional polymers possess outstanding uniqueness in fabricating intelligent devices such as sensors and actuators, but they are rarely used for converting mechanical energy into electric power. Here, a vitrimer based triboelectric nanogenerator (VTENG) is developed by embedding a layer of silver nanowire percolation network in a dynamic disulfide bond‐based vitrimer elastomer. In virtue of covalent dynamic disulfide bonds in the elastomer matrix, a thermal stimulus enables in situ healing if broken, on demand reconfiguration of shape, and assembly of more sophisticated structures of VTENG devices. On rupture or external damage, the structural integrity and conductivity of VTENG are restored under rapid thermal stimulus. The flexible and stretchable VTENG can be scaled up akin to jigsaw puzzles and transformed from 2D to 3D structures. It is demonstrated that this self‐healable and shape‐adaptive VTENG can be utilized for mechanical energy harvesters and self‐powered tactile/pressure sensors with extended lifetime and excellent design flexibility. These results show that the incorporation of organic materials into electronic devices can not only bestow functional properties but also provide new routes for flexible device fabrication.

We have measured the thermal conductivities of a 53-nm-thick and a 64-nm-thick tin dioxide (SnO2) nanobelt using a microfabricated device in the temperature range of 80–350 K. The uncertainty of the measurement result was estimated to be 10 percent. The thermal conductivities of the nanobelts were found to be significantly lower than the bulk values, and agree with our calculation results using a full dispersion transmission function approach. Comparison between measurements and calculation suggests that phonon-boundary scattering is the primary effect determining the thermal conductivities.

We have successfully fabricated and tested the electrochemical performance of supercapacitor electrodes consisting of Ni(OH)2 nanosheets coated on NiCo2O4 nanosheets grown on carbon fiber paper (CFP) current collectors. When the NiCo2O4 nanosheets are replaced by Co3O4 nanosheets, however, the energy and power density as well as the rate capability of the electrodes are significantly reduced, most likely due to the lower conductivity of Co3O4 than that of NiCo2O4. The 3D hybrid composite Ni(OH)2/NiCo2O4/CFP electrodes demonstrate a high areal capacitance of 5.2 F/cm2 at a cycling current density of 2 mA/cm2, with a capacitance retention of 79% as the cycling current density was increased from 2 to 50 mA/cm2. The remarkable performance of these hybrid composite electrodes implies that supercapacitors based on them have potential for many practical applications.

Abstract As the world population structure has already exhibited an inevitable trend of aging, technical advances that can provide better eldercare are highly desired. Knee osteoarthritis, one of the most common age‐associated diseases, can be effectively treated via total knee arthroplasty (TKA). However, patients are suffering from the recovery process due to inconvenience in post‐hospital treatment. Here, a portable, modular, and wearable brace for self‐assessment of TKA patients’ rehabilitation is reported. This system mainly consists of a force transducer for isometric muscle strength measurement and an active angle sensor for knee bending detection. Clinical experiments on TKA patients demonstrate the feasibility and significance of the system. Specifically, via brace‐based personalized healthcare, the TKA patients’ rehabilitation process is quantified in terms of myodynamia, and a definite rehabilitation enhancement is obtained. Additionally, new indicators, that is, isometric muscle test score, for evaluating TKA rehabilitation are proposed. It is anticipated that, as the cloud database is employed and more rehabilitation data are collected in the near future, the brace system can not only facilitate rehabilitations of TKA patients, but also improve life quality for geriatric patients and open a new space for remote artificial intelligence medical engineering.

The lack of efficient, low-cost, distributed energy collection methods is a vital factor restricting the application of the Internet of Things (IoT) in smart agriculture. This paper proposes a method based on triboelectric nanogenerator and electromagnetic generator to realize self-powered IoT nodes and self-powered sensors at the same time. An energy harvesting and sensing device based on electromagnetic-triboelectric hybrid generator (ES-ETHG) is designed. The peak power of ES-ETHG is 32.4 mW, which can supply power to IoT nodes for a long time with power management circuits. In addition, ES-ETHG can critically measure wind speed and wind level within the range of 3-15 m/s, and accurately detect wind direction within 2 s. Furthermore, the self-powered distributed weather sensing system based on ES-ETHG is developed to realize the remote collection of wind speed, wind direction, temperature, and humidity. This work proposes a solution for developing self-powered IoT and sensor in the field of smart agriculture.

Abstract The monitoring of micro‐droplets parameters is significant to the development of droplet microfluidics. However, existing monitoring methods have drawbacks such as high cost, interference with droplet movement, and even the potential for cross‐contamination. Herein, a micro‐droplets monitoring method (MDMM) based on liquid‐solid triboelectric nanogenerator (LS‐TENG) is proposed, which can realize non‐invasive and self‐powered monitoring of micro‐droplets in a microfluidic chip. The droplet frequency is monitored by voltage pulse frequency and a mathematical model is established to monitor the droplet length and velocity. Furthermore, this work constructs micro‐droplets sensor (MDS) based on the MDMM to carry out the experiment. The coefficients of determination ( R 2 ) of the fitting curves of the micro‐droplets frequency, length, and velocity monitoring are 0.998, 0.997, and 0.995, respectively. To prove the universal applicability of the MDMM, the micro‐droplets generated by different liquid media and channel structures are monitored. Eventually, a micro‐droplet monitoring system is built, which can realize the counting of micro‐droplets and the monitoring of droplet frequency and length. This work provides a novel approach for monitoring micro‐droplets parameters, which holds the potential to advance developments in the field of microfluidics.