Publications

'Peltier Coefficient' published in 'Encyclopedia of Nanotechnology'

On page 3549, V. V. Tsukruk and co-workers develop self-powered ultrathin flexible films for bio-tactile detection. Graphene oxide materials are engineered for robust self-powered tactile sensing applications harnessing their electrochemical reactivity. The simple quadruple electronic skin sensor can recognize nine spatial bio-tactile positions with high sensitivity and selectivity—an approach that can be expanded towards large-area flexible skin arrays.

The performance of air source heat pump systems is limited in extreme climate conditions, especially in heating mode, which may face defrosting problems, resulting in energy waste and reduced system efficiency. In order to improve this problem, this article uses 5% expanded graphite/paraffin composite phase change material to preheat the heat accumulator while heating the room, and evaluates the heating and defrosting performance of the air source heat pump based on composite phase change materials. Experimental results show that after using the regenerator, the defrost evaporation period in the defrost cycle is reduced by 42.2%, the resume heating period is reduced by 38.7%, the compressor power consumption is reduced by 42.1% compared with the original system, and the average outlet temperature of indoor unit increased by 8.1?C, and the indoor temperature fluctuation is reduced. This research is of great significance to the performance optimization of air source heat pumps under frost-prone conditions.

Hematite (α-Fe2O3) is a thermodynamically stable crystallographic phase of iron oxide and has attractive applications in many areas. By using a simple hydrothermal method, we synthesized smooth hematite microcubes and porous hematite microcubes. The as-synthesized microcubes have uniform edge lengths of about 1 μm. The magnetic, electrochemical properties and gas sensing performance to some organic gases were investigated, revealing the potential applications in various fields. By tuning the experimental parameters, such as source and solvent, we are able to tunably produce goethite (FeOOH) nanowires, and hematite nanoparticles, nanorods, and nanoplatelets and the formation mechanism was also discussed.

Electron energy loss spectroscopy in a high-resolution transmission electron microscope has recently been used with success to characterize the electronic properties of closed cage nanometer-size graphitic particles. In the plasmon region, the experimental data reveal interesting size-dependent variations, which are not yet fully understood. The difficulties encountered in the interpretation of the spectra are principally due to the lack of a complete theoretical treatment of the anisotropic dielectric response in nanometer-size particles. In order to obtain a better understanding of the experimental data we propose a model based on nonrelativistic local dielectric response theory for electrons penetrating through a nested concentric-shell fullerene or the so-called ``carbon onion.'' The anisotropy of the electronic properties of the sphere is taken into account via the frequency-dependent dielectric tensor of graphite. The model can be applied to simulate electron energy loss spectra as well as line scans through energy filtered images and allows thus a direct comparison to experimental data.

We report a methylammonium lead triiodide (MAPbI₃) perovskite-based photoenhanced triboelectric nanogenerator (TENG).

Abstract In this work, a self‐powered electrowetting valve (SPEV) driven by an energy‐harvesting triboelectric nanogenerator (TENG) is reported. The TENG (5 × 5 cm 2 ) can produce an open‐circuit voltage of 380 V by applying a mechanical stimulus, which is much higher than the actuation voltage of the SPEV (130 V). Once actuated, the electrowetting valve can be instantly switched on at a response time of 0.18 s, allowing liquid reagent to flow through the valve. The SPEV can be used for simultaneous addition of multiple reagents in an enzyme‐linked immunosorbent assay on a paper‐based microfluidic analytical device (µPAD). This assay involves a chromogenic reaction that achieves effective detection of alpha‐fetoprotein, a critical tumor marker for early diagnosis of liver cancer. The SPEV reported in this work can be potentially used in other complex multiprocedure µPADs, which will potentially enable portable, accessible, and cost‐effective assays for early diagnosis, food safety, pollution detection, etc.

The impaired differentiation ability of resident cells and disordered immune microenvironment in periodontitis pose a huge challenge for bone regeneration. Herein, we construct a piezoelectric hydrogel to rescue the impaired osteogenic capability and rebuild the regenerative immune microenvironment through bioenergetic activation. Under local mechanical stress, the piezoelectric hydrogel generated piezopotential that initiates osteogenic differentiation of inflammatory periodontal ligament stem cells (PDLSCs) via modulating energy metabolism and promoting adenosine triphosphate (ATP) synthesis. Moreover, it also reshapes an anti-inflammatory and pro-regenerative niche through switching M1 macrophages to the M2 phenotype. The synergy of tilapia gelatin and piezoelectric stimulation enhances in situ regeneration in periodontal inflammatory defects of rats. These findings pave a new pathway for treating periodontitis and other immune-related bone defects through piezoelectric stimulation-enabled energy metabolism modulation and immunomodulation.

The self-powered system is a promising concept for wireless networks due to its independent and sustainable operations without an external power source. To realize this idea, the triboelectric nanogenerator (TENG) was recently invented, which can effectively convert ambient mechanical energy into electricity to power up portable electronics. In this work, a self-powered smart window system was realized through integrating an electrochromic device (ECD) with a transparent TENG driven by blowing wind and raindrops. Driven by the sustainable output of the TENG, the optical properties, especially the transmittance of the ECD, display reversible variations due to electrochemical redox reactions. The maximum transmittance change at 695 nm can be reached up to 32.4%, which is comparable to that operated by a conventional electrochemical potentiostat (32.6%). This research is a substantial advancement toward the practical application of nanogenerators and self-powered systems.

Bioinspired electronics have dramatically spurred advances in artificial intelligence with unconventional logic functions. Herein, we propose a self-powered prototype for mechano-driven sequential logic based on a playmobile harnessed with a triboelectric nanogenerator (TENG), which is represented by dynamically interacting with the external environment and responding with featured mechanical Boolean logic function. Mechanical stimuli imposed on the triboelectric sensory neuron can be readily converted into spatiotemporal spikes, captured by a perceiving unit, and analyzed to deliver mechanical logic feedback. The prototype embodying sequential logic can successfully simulate mechanical race and hazard phenomena and deliver an effective solution. A complete mechanical Boolean logic is also reflected in an intelligent labyrinth-addressing process by hybridizing combinational and sequential logic information assisted by spatiotemporal triboelectric signals. This work presents the first prototype of a TENG embodying sequential logic, which is attractive for low-power mechano-driven logic and energy-autonomy processing for unexpected environmental information.