Publications by authors named "Pingan Hu"

Mental stress, a human's common emotion that is difficult to recognize and describe, can give rise to serious psychological disorders. Skin and sweat are easily accessible sources of biomarkers and bio-signals that contain information about mental stress. It is challenging for current wearable devices to monitor psychological stress in real-time with a non-invasive manner.

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The real-time monitoring of low-concentration cytokines such as TNF-α in sweat can aid clinical physicians in assessing the severity of inflammation. The challenges associated with the collection and the presence of impurities can significantly impede the detection of proteins in sweat. This issue is addressed by incorporating a nanosphere array designed for automatic sweat transportation, coupled with a reusable sensor that employs a Nafion/aptamer-modified MoS field-effect transistor.

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High-performance tactile sensors with skin-sensing properties are crucial for intelligent perception in next-generation smart devices. However, previous studies have mainly focused on the sensitivity and response range of tactile sensation while neglecting the ability to recognize object softness. Therefore, achieving a precise perception of the softness remains a challenge.

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Single-crystal metal foils with high-index facets are currently being investigated owing to their potential application in the epitaxial growth of high-quality van der Waals film materials, electrochemical catalysis, gas sensing, and other fields. However, the controllable synthesis of large single-crystal metal foils with high-index facets remains a great challenge because high-index facets with high surface energy are not preferentially formed thermodynamically and kinetically. Herein, single-crystal nickel foils with a series of high-index facets are efficiently prepared by applying prestrain energy engineering technique, with the largest single-crystal foil exceeding 5×8 cm in size.

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The exploration and synthesis of novel materials are integral to scientific and technological progress. Since the prediction and synthesis of two-dimensional (2D) materials, it is expected to play an important role in the application of industrialization and the information age, resulting from its excellent physical and chemical properties. Currently, researchers have effectively utilized a range of material synthesis techniques, including mechanical exfoliation, redox reactions, chemical vapor deposition, and chemical vapor transport, to fabricate two-dimensional materials.

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Quest for ultrathin and highly effective anticorrosion coating films is critical for both fundamental community of materials science and industrial economics. A two-dimensional hexagonal boron nitride (h-BN) film is a newly developed effective anticorrosion material due to its superior impermeability, thermal stability, and chemical stability. However, research in growth and anticorrosion properties of large-area dense h-BN coating films still lies in its infancy.

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Multifunctional capability and low coupling electronic skin (e-skin) is of great significance in advanced robot systems interacting with the human body or the external environment directly. Herein, a multifunctional e-skin system via vertical integrated different sensing materials and structures is presented. The multifunctional e-skin has capacity sensing the proximity, pressure, temperature, and relative humidity simultaneously, with scope of 100-0 mm, 0-30 N, 20-120 °C and 20-70%, respectively.

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The multiple requirements of optical transmittance, high shielding effectiveness, and long-term stability bring considerable challenge to electromagnetic interference (EMI) shielding in the fields of visualization windows, transparent optoelectronic devices, and aerospace equipment. To this end, attempts were hereby made, and based on high-quality single crystal graphene (SCG)/hexagonal boron nitride (h-BN) heterostructure, transparent EMI shielding films with weak secondary reflection, nanoscale ultra-thin thickness and long-term stability were finally realized by a composite structure. In this novel structure, SCG was adopted as the absorption layer, while sliver nanowires (Ag NWs) film acted as the reflection layer.

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Near-infrared (NIR) synaptic devices integrate NIR optical sensitivity and synaptic plasticity, emulating the basic biomimetic function of the human visual system and showing great potential in NIR artificial vision systems. However, the lack of semiconductor materials with appropriate band gaps for NIR photodetection and effective strategies for fabricating devices with synaptic behaviors limit the further development of NIR synaptic devices. Here, a two-terminal NIR synaptic device consisting of the InSe/MoS heterojunction has been constructed, and it exhibits fundamental synaptic functions.

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Two-dimensional (2D) materials have attracted great attention in the field of photodetection due to their excellent electronic and optoelectronic properties. However, the weak optical absorption caused by atomically thin layers and the short lifetime of photocarriers limit their optoelectronic performance, especially for weak light detection. In this work, we design a high-gain photodetector induced by carrier recirculation based on a vertical InSe/GaSe heterojunction.

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Self-powered photodetectors have attracted widespread attention due to their low power consumption which can be driven by the built-in electric field instead of external power, but it is very difficult to achieve high responsivity and fast response speed concurrently. Here, a self-powered photodetector with light-induced electric field enhancement based on a 2D InSe/WSe /SnS van der Waals heterojunction is designed. The light-induced electric field derived from the photo-generated electrons of SnS accumulated at the SnS /WSe interface produces an additional negative gate voltage applied to the WSe layer, which enhances the built-in electric field in the InSe/WSe /SnS heterojunction.

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Background: The diagnostic criteria for Parkinson's disease (PD) remain complex, which is especially problematic for nonmovement disorder experts. A test is required to establish a diagnosis of PD with improved accuracy and reproducibility.

Objective: The study aimed to investigate the sensitivity and specificity of tests using sniffer dogs to diagnose PD.

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Two-dimensional (2D) InSe is a good candidate for high-performance photodetectors due to its good light absorption and electrical transport properties. However, 2D InSe photodetectors usually endure a large driving voltage, and 2D InSe-based heterojunction photodetectors require complex fabrication processes. Here, we demonstrate high-performance self-powered InSe-based photoelectrochemical (PEC) photodetectors using electrochemical intercalated ultrathin InSe nanosheets.

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Tuning the optical and electrical properties of two-dimensional (2D) hexagonal boron nitride (hBN) is critical for its successful application in optoelectronics. Herein, we report a new methodology to significantly enhance the optoelectronic properties of hBN monolayers by substitutionally doping with sulfur (S) on a molten Au substrate using chemical vapor deposition. The S atoms are more geometrically and energetically favorable to be doped in the N sites than in the B sites of hBN, and the S 3p orbitals hybridize with the B 2p orbitals, forming a new conduction band edge that narrows its band gap.

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Two-dimensional (2D) integrated circuits based on graphene (Gr) heterostructures have emerged as next-generation electronic devices. However, it is still challenging to produce high-quality and large-area Gr/hexagonal boron nitride (-BN) vertical heterostructures with clear interfaces and precise layer control. In this work, a two-step metallic alloy-assisted epitaxial growth approach has been demonstrated for producing wafer-scale vertical hexagonal boron nitride/graphene (-BN/Gr) heterostructures with clear interfaces.

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Two-dimensional (2D) bismuth oxychalcogenide (BiOX, X refers to S, Se, and Te) is one type of rising semiconductor with excellent electrical transport properties, high photoresponse, and good air stability. However, the research on 2D BiOS is limited. In this work, ultrathin BiOS nanosheets are synthesized by a facile and eco-friendly chemical synthesis method at room temperature.

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The monolayer MoSbased photodetectors have been widely investigated, which show limited photoelectric performances due to its low light absorption and uncontrollable adsorbates. In this paper, we present a MoS-based hybrid nanoscrolls device, in which one-dimensional nanoscrollsof MoSis hybridized with carbon quantum dots (CQDs). This device architecture effectively enhanced the photodetection performance.

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Biomimetic eyes, with their excellent imaging functions such as large fields of view and low aberrations, have shown great potentials in the fields of visual prostheses and robotics. However, high power consumption and difficulties in device integration severely restrict their rapid development. In this study, an artificial synaptic device consisting of a molybdenum disulfide (MoS ) film coated with an electron injection enhanced indium (In) layer is proposed to increase the channel conductivity and reduce the power consumption.

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With the rapid development of artificial intelligence and neural network computing, the requirement for information storage in computing is gradually increasing. Floating gate memories based on 2D materials has outstanding characteristics such as non-volatility, optical writing, and optical storage, suitable for application in photonic in-memory computing chips. Notably, the optoelectronic memory requires less optical writing energy, which means lower power consumption and greater storage levels.

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2D organic crystals exhibit efficient charge transport and field-effect characteristics, making them promising candidates for high-performance nanoelectronics. However, the strong Fermi level pinning (FLP) effect and large Schottky barrier between organic semiconductors and metals largely limit device performance. Herein, by carrying out temperature-dependent transport and Kelvin probe force microscopy measurements, it is demonstrated that the introducing of 2D metallic 1T-TaSe with matched band-alignment as electrodes for F CuPc nanoflake filed-effect transistors leads to enhanced field-effect characteristics, especially lowered Schottky barrier height and contact resistance at the contact and highly efficient charge transport within the channel, which are attributed to the significantly suppressed FLP effect and appropriate band alignment at the nonbonding van der Waals (vdW) hetero-interface.

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Different acoustic wave modes are required for effective implementation of biosensing and liquid actuation functions in an acoustic wave-based lab-on-a-chip. For efficient sensing in liquids, shear waves (either a thickness-shear bulk wave or a shear-horizontal surface acoustic wave) can achieve a high sensitivity, without significant loss of acoustic wave energy. On the other hand, longitudinal bulk waves or out-of-plane displacement waves (such as Rayleigh waves) enable efficient sampling functions and liquid manipulation.

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Based on archival materials, the Xiangya's anti-epidemic history in a century from its establishment to 2020 is divided into 4 stages. The first stage (1906-1926), Edward Hicks Hume and YAN Fuqing, the founders of Xiangya, prevented and controlled smallpox and plague. The second stage (1929-1953), during the resumption of Xiangya, students prevented and controlled cholera, plague, dysentery, typhus, and other infectious diseases.

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Multilayer van der Waals (vdWs) semiconductors have promising applications in high-performance optoelectronic devices. However, photoconductive photodetectors based on layered semiconductors often suffer from sizeable dark currents and high external driving bias voltages. Here, we report vertical van der Waals heterostructures (vdWHs) consisting of multilayer indium selenide (InSe) and tellurium (Te).

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Atomically thin hexagonal boron nitride (h-BN) is an emerging star of 2D materials. It is taken as an optimal substrate for other 2D-material-based devices owing to its atomical flatness, absence of dangling bonds, and excellent stability. Specifically, h-BN is found to be a natural hyperbolic material in the mid-infrared range, as well as a piezoelectric material.

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