A magnetostrictive self-powered biosensor based on Au-BaTiO3-FeGa & PDMS

Qiang Zhang,Meng Xu,Yan Liu,Chunyan Zhang,Rui Zhang,Zhiyuan Fu,Jianlong Ji,Riguang Zhang,Shengbo Sang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

Piezoelectric flexible sensors have been used to detect biomolecules such as sweat and glucose because oftheir passive, simple structure and high sensitivity. This paper proposes a novel flexible piezoelectric Au-BaTiO3-FeGa & PDMS biosensor in which magnetostrictive deformation amplifies the surface stress generatedby biomolecules combining on the thin film. The modification process of bovine serum albumin(BSA) binding with the sensor was initially determined by the first principles approach. Then, the sensingmechanism was verified by finite-element simulation. Based on the simulation results, flexible Au-BaTiO3-FeGa & PDMS biosensors were prepared, modified, and measured. The structure, modification,and detection of the sensors were analyzed by digital microscopy, Fourier transform infrared spectrometry(FTIR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The responses ofthe biosensors detecting different BSA solution concentrations under magnetic fields were then investigated. Experimental results indicate that the biosensor has the highest sensitivity under a magnetic fieldof 30 mT.

Cross-Linked Low Dielectric Nanoporous Polycarbosilane Derived from Benzocyclobutene-Containing Poly(carbosilane)-b-Polylactide Block Copolymer

Shengbo Zhang,Huan Hu,Hongtao Yu,Yawen Huang,Junxiao Yang 한국고분자학회 2017 Macromolecular Research Vol.25 No.4

Low dielectric materials show great application potential in future microelectronic industry. In this study, benzocyclobutene-functionalized polycarbosilane derived block copolymer, poly(carbosilane-b-lactide), was synthesized via sequential anionic polymerization of silacyclobutene and ring-opening polymerization of lactide. The block copolymer revealed microphase-separation behavior to form a well-defined morphology. Simultaneously, the sacrifice of polylactide blocks by thermal decomposition and thermally-induced reaction of benzocyclobutene produces cross-linked nanoporous polycarbosilane (PBCS). The dielectric constant of this nanoporous material reaches to around 2.1.

Terahertz Characteristics of Hydroxygraphene Based on Microfluidic Technology

Boyan Zhang,Siyu Qian,Bo Peng,Bo Su,Zhuang Peng,Hailin Cui,Shengbo Zhang,Cunlin Zhang 한국광학회 2023 Current Optics and Photonics Vol.7 No.4

Hydroxygraphene as a kind of functionalized graphene has important applications in composite, photoelectric and biological materials. In the present study, THz and microfluidic technologies were implemented to study the THz transmission characteristics of hydroxygraphene with different concentrations and residence times in magnetic and electric fields. The results show that the THz transmission intensity decreases with the increase in sample concentration and duration of an applied electric field, while it increases by staying longer in the magnetic field. The phenomenon is analyzed and explained in terms of hydrogen bond, conductivity and scattering characteristics. The results establish a foundation for future research on the THz absorption characteristics of liquid graphene based on microfluidic technology in different external environments. It also provides technical support for the application and development of graphene in THz devices.

An Investigation of the Terahertz Absorption Characteristics of a Graphene Oxide Aqueous Solution Using Microfluidic Technology

Ningyi Cai,Boyan Zhang,Qinghao Meng,Siyu Qian,Bo Su,Hailin Cui,Shengbo Zhang,Cunlin Zhang 한국광학회 2023 Current Optics and Photonics Vol.7 No.2

The vibratory and rotational levels of many biological macromolecules lie in the terahertz (THz) band, which means that THz techniques can be used to identify and detect them. Moreover, since the biological activity of most biomolecules only becomes apparent in aqueous solution, we use microfluidic technology to study the biological properties of these biomolecules. THz time-domain spectroscopy was used to study the THz absorption characteristics of graphene oxide (GO) aqueous solution at different concentrations and different exposure times in fixed electric or magnetic fields. The results show that the spectral characteristics of the GO solution varied with the concentration: as the concentration increased, the THz absorption decreased. The results also show that after placing the solution in an external electric field, the absorption of THz first increased and then decreased. When the solution was placed in a magnetic field, the THz absorption increased with the increase in standing time. In this paper, these results are explained based on considerations of what is occurring at the molecular scale. The results of this study provide technical support for the further study of GO and will assist with its improved application in various fields.

Prediction of Basketball Players' behavior based on Radial Basis Function Neural Network

Shengbo Liao,Deming Zhang,Haitao Yang 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.12

An approach based on online RBFNN is proposed to predict the ball-carrier's behavior shooting, passing and dribbling in basketball matches. In order to describe the factors affecting the behavior of ball carrier, artificial potential field (APF)-based player information is introduced to model the court situation of all players after tracking and vision range determination, then a feature vector is formed as the input of the online RBF neural network. The behavior prediction of the ball carrier is solved by the online RBF neural network based on GIRAN learning algorithm. Compared with the offline RBF neural network, the online neural network can adjust both structure and parameters to basketball matches, thus the prediction accuracy is improved to some extent.

Accuracy Estimation of a Classifier Based on the Differences in Samples

Min Zhang,Shengbo Yu 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.11

The classification accuracy is an important standard to measure the quality of the classifier. Usually, the classification accuracy is assessed later, not during the classification process. Problems such as classification accuracy drops cannot be timely and effectively found. It is necessary that marking test samples when estimating classification accuracy. It is a problem that we care about that how much is the classification accuracy when a group of new samples obtained. The problem must be concerned when using and improving the classifier in the case of growing data. To solve this problem, this paper put forward different estimates from different perspectives which based on the difference between samples. One estimate is based on the difference in samples distribution, which is from the Bayesian criterion. Another estimate is based on the difference in each sample instance, which is from the K nearest neighbor classification. Classification accuracy is also estimated by using the artificial neural networks, which combine the characteristics of the above two methods. And results show the proposed methods have good effects.

Fabrication and characterization of silicon nanostructures based on metal-assisted chemical etching

Wendong Zhang,Jie Hu,Xuge Fan,Shengbo Sang,Pengwei Li,Gang Li,Yongjiao Sun 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.1

We present a facile method to fabricate one-dimensional Si nanostructures based on Ag-induced selective etching of silicon wafers. To obtain evenly distributed Si nanowires (SiNWs), the fabrication parameters have been optimized. As a result, a maximum of average growth rate of 0.15 μm/min could be reached. Then, the fabricated samples were characterized by water contact angle (CA) experiments. As expected, the as-etched silicon samples exhibited a contact angle in the range of 132o-136.5o, whereas a higher contact angle (145o) could be obtained by chemical modification of the SiNWs with octadecyltrichlorosilane (OTS). Additionally, Raman spectra experiments have been carried out on as-prepared nanostructures, showing a typical decreasing from 520.9 cm−1 to 512.4 cm−1 and an asymmetric broadening, which might be associated with the phonon quantum confinement effect of Si nanostructures.

Flexible and Highly Sensitive Piezoresistive Pressure Sensor with Sandpaper as a Mold

Wendan Jia,Qiang Zhang,Yongqiang Cheng,Dong Zhao,Yan Liu,Wendong Zhang,Shengbo Sang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

Flexible pressure sensors based on piezoresistive induction have recently become a research hotspot due to the simple device structure, low energy consumption, easy readout mechanism and excellent performance. For practical applications, flexible pressure sensors with both high sensitivity and low-cost mass production are highly desirable. Herein, this paper presents a high-sensitivity piezoresistive pressure sensor based on a micro-structured elastic electrode, which is low cost and can be mass-produced by a simple method of sandpaper molding. The microstructure of the electrode surface under external pressure causes a change in the effective contact area and the distance between the electrodes, which exhibits great pressure sensitivity. The test results show that the surface structure is twice as sensitive as the planar structure under low pressure conditions. This is because of the special morphology of silver nanowires (AgNWs), which exhibits the tip of nanostructures on the surface and realizes the quantum tunneling mechanism. The sensor has high sensitivity for transmitting signals in real time and it can also be used to detect various contact actions. The low cost mass production and high sensitivity of flexible pressure sensors pave the way for electronic skin, wearable healthcare monitors and contact inspection applications.

Mixed Reinforcement Learning for Efficient Policy Optimization in Stochastic Environments

Yao Mu,Baiyu Peng,Ziqing Gu,Shengbo Eben Li,Chang Liu,Bingbing Nie,Jianfeng Zheng,Bo Zhang 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10

Reinforcement learning has the potential to control stochastic nonlinear systems in optimal manners successfully. We propose a mixed reinforcement learning (mixed RL) algorithm by simultaneously using dual representations of environmental dynamics to search the optimal policy. The dual representation includes an empirical dynamic model and a set of state-action data. The former can embed the designer’s knowledge and reduce the difficulty of learning, and the latter can be used to compensate the model inaccuracy since it reflects the real system dynamics accurately. Such a design has the capability of improving both learning accuracy and training speed. In the mixed RL framework, the additive uncertainty of stochastic model is compensated by using explored state-action data via iterative Bayesian estimator (IBE). The optimal policy is then computed in an iterative way by alternating between policy evaluation (PEV) and policy improvement (PIM). The effectiveness of mixed RL is demonstrated by a typical optimal control problem of stochastic non-affine nonlinear systems (i.e., double lane change task with an automated vehicle).

Preparation and In Vitro Characterization of Gelatin Methacrylate for Corneal Tissue Engineering

Yan Yayun,Cao Yanyan,Cheng Rong,Shen Zhizhong,Zhao Yajing,Zhang Yixia,Zhou Guohong,Sang Shengbo 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.1

BACKGROUND: Corneal disease is second only to cataract considered as the leading cause of blindness in the world, with high morbidity. Construction of corneal substitutes in vitro by tissue engineering technology to achieve corneal regeneration has become a research hotspot in recent years. We conducted in-depth research on the biocompatibility, physicochemical and mechanical properties of rat bone marrow mesenchymal stem cells (rBM-MSCs)-seeded gelatin methacrylate (GelMA) as a bioengineered cornea. METHODS: Four kinds of GelMA with different concentrations (7, 10, 15 and 30%) were prepared, and their physicchemical, optical properties, and biocompatibility with rBM-MSCs were characterized. MTT, live/dead staining, cell morphology, immunofluorescence staining and gene expression of keratocyte markers were performed. RESULTS: 7%GelMA hydrogel had higher equilibrium water content and porosity, better optical properties and hydrophilicity. In addition, it is more beneficial to the growth and proliferation of rBM-MSCs. However, the 30%GelMA hydrogel had the best mechanical properties, and could be more conducive to promote the differentiation of rBM-MSCs into keratocyte-like cells. CONCLUSION: As a natural biological scaffold, GelMA hydrogel has good biocompatibility. And it has the ability to promote the differentiation of rBM-MSCs into keratocyte-like cells, which laid a theoretical and experimental foundation for further tissue-engineered corneal stromal transplantation, and provided a new idea for the source of seeded cells in corneal tissue engineering.