Zhenlong Huang

Simultaneously Harvesting Thermal and Mechanical Energies based on Flexible Hybrid Nanogenerator for Self-Powered Cathodic Protection.

Metal corrosion occurs anytime and anywhere in nature and the corrosion prevention has a great significance everywhere in national economic development and daily life. Here, we demonstrate a flexible hybrid nanogenerator (NG) that is capable of simultaneously or individually harvesting ambient thermal and mechanical energies and used for a self-powered cathodic protection (CP) system without using an external power source. Because of its double peculiarities of both pyroelectric and piezoelectric properties, a polarized poly(vinylidene fluoride) (PVDF) film-based NG was constructed to scavenge both thermal and mechanical energies. As a supplementary, a triboelectric NG was constructed below the pyro/piezoelectric NG to grab ambient mechanical energy. The output power of the fabricated hybrid NG can be directly used to protect the metal surface from the chemical corrosion. Our results not only verify the feasibility of self-powered CP-based NGs, but also expand potential self-powered applications.

Highly stretchable and shape-controllable three-dimensional antenna fabricated by “Cut-Transfer-Release” method

Recent progresses on the Kirigami-inspired method provide a new idea to assemble three-dimensional (3D) functional structures with conventional materials by releasing the prestrained elastomeric substrates. In this paper, highly stretchable serpentine-like antenna is fabricated by a simple and quick “Cut-Transfer-Release” method for assembling stretchable 3D functional structures on an elastomeric substrate with a controlled shape. The mechanical reliability of the serpentine-like 3D stretchable antenna is evaluated by the finite element method and experiments. The antenna shows consistent radio frequency performance with center frequency at 5.6 GHz during stretching up to 200%. The 3D structure is also able to eliminate the hand effect observed commonly in the conventional antenna. This work is expected to spur the applications of novel 3D structures in the stretchable electronics.

Ultrafast response flexible breath sensor based on vanadium dioxide

Real-time monitoring of breath can provide clinically relevant information about apnea syndrome and other important aspects of human physiology. Here, we introduce a flexible skin-like breath sensor developed by transfer-printing vanadium dioxide (VO2) thin films on PDMS substrates. This flexible breath sensor can conformably laminate on the skin under the nose with different curvatures and operate at different environment temperatures through day and night. Attributed to the high temperature coefficient of resistance of VO2, the enhanced breath sensing performance was demonstrated and the response time and recovery time can be as fast as 0.5 s. The excellent sensing performance and fast response time indicate that the VO2-based breath sensor is feasible in monitoring breath for prevention of apnea syndrome.

Microstructure dependence of heat sink constructed by carbon nanotubes for chip cooling

Carbon nanotube (CNT) arrays with aligned growth orientation and sponge CNTs which consist of flocculent carbon fibers with tiny CNTs on their surface were synthesized by chemical vapor deposition. Heat sinks based on CNT arrays or sponge CNTs were made to investigate their heat dissipation performance. It is found that their microstructures have strong impacts on the thermal performance by changing the coefficient of air convection. The long CNT arrays have good heat dissipation performance even under natural convection for its aligned structure and large contacting area with the air, while the sponge CNTs show larger improvement in heat dissipation ability under airflow due to their porous structure. The results give a good reference for developing low-cost, light-weight, and high-performance CNT-based heat sinks for chip cooling under different working conditions.

ZnO particles enhanced graphene-based hybrid light sensors

Graphene with excellent mechanical properties shows potential applications in flexible devices. By decorating graphene with ZnO nanoparticles, the response of graphene-based flexible light sensor to light was enhanced. The light sensor showed different response rates with light intensities under different wavelength which indicated that the as-designed sensor can be used to detect the wavelength and intensity of light simultaneously. The microstructures and photonic properties of the hybrid device revealed that the interface played an important role on the performance of device. This result confirmed the method to prepare graphene/ZnO hybrid light sensor are convenient and economical, which may be applied in wearable devices.

Chip cooling with carbon nanotube heat sink

In this paper, lightweight heat sinks based on carbon nanotubes (CNTs) are presented. CNTs were attached on the surface of silicon chips and their heat dissipation performance were monitored. As the morphology of heat sinks is an important factor for the heat dissipation efficiency, two types of CNTs, CNT arrays and sponge CNTs, were used here. Besides, the influence of airflow on the two kinds of CNTs based heat sink was observed by controlling the wind speed. This work gives an excellent reference for a low-cost and high-performance micro-heat sink in the future.