Article
Physics, Multidisciplinary
Fatemeh Ahmadzadeh, Ali Bahrami
Summary: A two-dimensional gradient-index phononic crystal composed of aluminum scatterers in an air matrix has been designed and simulated. The path of waves inside the structure is shown using analytical solutions. By increasing the filling factor, the structure can be mechanically tuned, resulting in a shift in the focal point while maintaining a nearly constant spot size.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Biochemistry & Molecular Biology
Yuqi Jin, Arup Neogi
Summary: This study demonstrates the detections and mappings of a solid object using a thermally tunable solid-state phononic crystal lens for potential use in future long-distance detection. By changing the temperature, the focal length of the phononic crystal lens can be adjusted, and experiments in water show a higher signal-to-noise ratio with the thermo-reversible tunable lens.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Materials Science, Multidisciplinary
Binming Liang, Xiao Huang, Jihong Zheng
Summary: This paper proposes the use of a graded-index Photonic crystal (GPC) flat lens to improve image resolution, and presents a two-dimensional (2D) GPC structure based on a silicon medium. Numerical simulations show that when the imaging area is filled with air, the full width at half maximum (FWHM) value of a single image is 0.362 lambda, and the images of two point sources 0.57 lambda apart can be distinguished.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Materials Science, Multidisciplinary
Fan Yang, Zhuhua Tan, Xu Han, Chongdu Cho
Summary: A graded negative refraction index phononic crystal plate lens was designed using a method of rotating scatterers, showing significant focusing efficiency, and providing a new way for fabricating energy harvesting devices.
RESULTS IN PHYSICS
(2021)
Article
Physics, Applied
Jyotsna Dhillon, Andrey Bozhko, Ezekiel Walker, Arup Neogi, Arkadii Krokhin
Summary: A phononic crystal of aluminum rods with asymmetric cross section in water is used to study Anderson localization of sound. Different configurations of scatterers are explored, showing weakened transmission in the direction of disorder and extended wave propagation in the ordered direction. The localization length is controlled by the degree of disorder, with experimental observations confirming theoretical predictions for particular modes.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Mechanical
Rongjiang Tang, Taoqi Lu, Weiguang Zheng
Summary: This study aims to achieve small-size control of large wavelengths in phononic crystals. Through finite element method calculations and analysis, an ultrawide band gap has been successfully achieved. It was found that the presence of silicone rubber is crucial for obtaining low-frequency ultra-wideband gap.
JOURNAL OF VIBRATION ENGINEERING & TECHNOLOGIES
(2023)
Article
Physics, Multidisciplinary
Dan-Feng Wang, Yu-Qi Wang, Zheng-Hua Qian, Tomohiro Tachi, Kuo-Chih Chuang
Summary: Origami as an art form has been utilized to create a gradient-index phononic crystal lens, allowing for focusing and modulation of incident waves through folding angles. The intricate design of the folding structure enables originally planar waves to be effectively focused towards the center axis.
Article
Engineering, Electrical & Electronic
M. Mirmozafari, M. Tursunniyaz, H. Luyen, J. H. Booske, N. Behdad
Summary: This study presents a cylindrical, multibeam, modified Luneburg lens antenna design with features such as low-profile, good impedance match, high gain, and wide angle scanning capability. By tapering the thickness of a dielectric disk along its radius, the required refractive index profile of the lens is achieved in a nondispersive manner. The use of the same dielectric material for the lens and the interior of the waveguide feeds enables a smooth impedance transition and ensures invariant azimuthal scanning.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Optics
Rafael Navarro, Sergio Baquedano, Ana Sanchez-Cano
Summary: A new type of lens with two gradients of refractive index and curvature is introduced, resembling the structure of an onion with each layer being a meniscus lens. The internal distribution adapts to the external geometry, with consideration of a constant gradient of the curvature radius.
Article
Physics, Applied
Ahmed Allam, Karim Sabra, Alper Erturk
Summary: The study demonstrates the enhancement of sound energy harvesting by focusing acoustic waves using a 3D-printed gradient-index phononic crystal lens. Numerical simulations and experimental validations show excellent agreement, with the lens significantly increasing the intensity of sound energy and enabling micro-Watt level power output. This technology has potential applications for wireless sensors and other low-power electronic components.
APPLIED PHYSICS LETTERS
(2021)
Article
Optics
Abrar Islam, Firoz Haider, Rifat Ahmmed Aoni, Rajib Ahmed
Summary: A photonic crystal fiber-based surface plasmon resonance sensor for rapid detection and quantification of novel coronavirus has been successfully developed and investigated numerically. The proposed sensor demonstrates viable detections of different components of the virus and shows promising sensitivity and resolution for viral RNA detection. The compact photonic sensor is well-suited for rapid point-of-care COVID testing.
Article
Engineering, Mechanical
Tian-Xue Ma, Zheng-Yang Li, Chuanzeng Zhang, Yue-Sheng Wang
Summary: This paper presents a phononic crystal Luneburg lens for harvesting the mechanical energy of Rayleigh surface waves. The lens is formed by a square-latticed phononic crystal with holes drilled periodically in an aluminum matrix. A piezoelectric disk is attached at the focal point of the lens to convert the mechanical energy into electricity. The results show that the electric power outputs of the PnC Luneburg lens harvester are significantly enhanced compared to the reference harvester on a homogeneous aluminum matrix, with an amplification ratio over 14 for both the &UGamma;X and &UGamma;M directions.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Nanoscience & Nanotechnology
Suli Wu, Jinjian Nan, Yue Wu, Zhipeng Meng, Shufen Zhang
Summary: In this work, a composite PC structure is designed for anticounterfeiting purposes, which can be decoded by an alcohol tissue and shows a vivid low-angle-dependent structural color. To enhance the anticounterfeiting ability, a double-sided label with different encryption patterns is also designed.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Biochemical Research Methods
Rafael Navarro, Veronica Lockett-Ruiz, Jose L. Lopez
Summary: In this paper, we present the formulation of a paraxial ray transfer matrix for onion-type GRIN lenses. The matrix is computed by multiplying translation and refraction matrices corresponding to the layers inside the lens. We derive the ABCD matrix using a differential approximation for the layer thickness, and calculate its elements by integrating the elements of a single-layer matrix. The resulting matrix offers a compact and simple expression for the total lens power.
BIOMEDICAL OPTICS EXPRESS
(2022)
Article
Optics
Zhang-Lang Lin, Pavel Loiko, Huang-Jun Zeng, Wen-Ze Xue, Ge Zhang, Simone Normani, Patrice Camy, Valentin Petrov, Xavier Mateos, Haifeng Lin, Haohai Yu, Huaijin Zhang, Junhai Liu, Li Wang, Weidong Chen
Summary: We present a Kerr-lens mode-locked laser utilizing an Yb3+-doped disordered calcium lithium niobium gallium garnet (Yb:CLNGG) crystal. By pumping with a spatially single-mode Yb fiber laser at 976nm, the Yb:CLNGG laser generates soliton pulses with a duration of 31 fs at 1056.8nm, achieving an average output power of 66mW and a pulse repetition rate of approximately 77.6MHz via soft-aperture Kerr-lens mode-locking. The Kerr-lens mode-locked laser reaches a maximum output power of 203mW for slightly longer pulses of 37fs at an absorbed pump power of 0.74W, corresponding to a peak power of 62.2kW and an optical efficiency of 20.3%.
Article
Materials Science, Multidisciplinary
Lei Deng, Shuaishuai Sun, Matthew Daniel Christie, Wenxing Li, Donghong Ning, Haiping Du, Shiwu Zhang, Weihua Li
Summary: This paper presents an innovative variable stiffness and variable damping magnetorheological (MR) actuation system to solve the overshoot and long settling time problems in the positioning control of robotic arms. By controlling the stiffness and damping of the VSVD unit, the system can reduce overshoot and settling time of the robotic arm with less energy consumption. Both numerical and experimental results demonstrate that the proposed VSVD actuation system is an effective solution for robotic arm positioning control problems.
JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
(2023)
Article
Acoustics
Shiwei Liu, Gaoliang Peng, Zhixiong Li, Weihua Li
Summary: This paper focuses on the analytical jump criteria problem for a class of Duffing systems based on the concave-convex property. The defined single critical jump point is proved to be an inflection point, and the analytical jump-avoidance criteria under different excitations are established. The sensitivities of dynamic parameters are discussed, and the effectiveness of the proposed method is demonstrated through numerical simulations and comparisons.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Chemistry, Physical
Yue Chen, Xuanhan Chen, Zhenhong Zhu, Mingyuan Sun, Shen Li, Minfeng Gan, Shi-Yang Tang, Weihua Li, Shiwu Zhang, Lining Sun, Xiangpeng Li
Summary: This study developed foam-core liquid metal (FCLM) droplets that can be manipulated in 3D in an electrolyte. The FCLM droplets are made by coating liquid metal on the surface of a copper-grafted foam sphere and actuated by electrically inducing Marangoni flow. Multiple droplets can form 3D structures, showing potential for wider applications.
Article
Automation & Control Systems
Yulin Liao, Donghong Ning, Pengfei Liu, Haiping Du, Weihua Li
Summary: This article presents a versatile electrically interconnected suspension system for vehicles, which offers variable iner-tance and variable damping in the heave direction and variable stiffness in the roll direction. The system achieves suspension interconnection electrically, providing improved design flexibility, energy efficiency, and system response. Test results show that the proposed system has significant performance improvements compared to a passive suspension, reducing resonance by 13.0%.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Chemistry, Physical
Liping Gong, Tingting Xuan, Sheng Wang, Haiping Du, Weihua Li
Summary: Researchers have developed a versatile liquid metal-based triboelectric nanogenerator (LM-TENG) device, which integrates shear stiffening elastomer (SSE) with liquid metal (LM) and electrothermal aluminum foil. The LM-TENG demonstrated good energy harvesting capacity and excellent electrothermal and anti-impact performance. This study provides a new strategy for designing multifunctional sensors and paves the way for intelligent wearable electronics, personal healthcare, and safeguards.
Article
Engineering, Electrical & Electronic
Shengfeng Zhu, Ning Gong, Jian Yang, Shiwu Zhang, Xinglong Gong, Weihua Li, Shuaishuai Sun
Summary: Magnetorheological (MR) technology is controllable and has provided effective solutions to engineering bottleneck problems. Designing a rotary MR damper with a high torque-volume ratio is challenging, especially for specific applications with limited space. To solve this problem, a rotary damper based on MR bearings was designed and evaluated, which saves space and provides high torque. Quasistatic testing shows that this rotary damper achieves a high torque-volume ratio of 190 kN/m(2), nearly four times higher than existing rotary MR dampers, effectively satisfying high torque requirements in limited space.
Article
Engineering, Electrical & Electronic
Matthew Daniel Christie, Shuaishuai Sun, Lei Deng, Haiping Du, Shiwu Zhang, Weihua Li
Summary: The performance of a magnetorheological-fluid-based variable stiffness actuator leg under high impact forces was evaluated through optimal tuning and control of stiffness and damping properties. Drop testing experiments were conducted to assess the leg's performance at different drop heights and payload masses. The results demonstrated the importance of considering both stiffness and damping in the design of legged robots for high impact force resistance, and highlighted the efficacy of the proposed magnetorheological-fluid-based leg design for this purpose.
Article
Computer Science, Artificial Intelligence
Yan Yan, Haiping Du, Qing-Long Han, Weihua Li
Summary: This study presents a real-time switching topology technique to improve the performance of connected autonomous vehicles under poor communication. A sliding mode controller is designed for a nonlinear heterogeneous vehicle model with packet loss, and Lyapunov analysis is applied to ensure stability. A two-step switching topology framework is introduced to optimize the platoon's performance. Numerical simulations show significant improvements in platoon tracking ability, fuel efficiency, and driving comfort.
IEEE TRANSACTIONS ON INTELLIGENT VEHICLES
(2023)
Article
Chemistry, Multidisciplinary
Qingtian Zhang, Hongda Lu, Guolin Yun, Liping Gong, Zexin Chen, Shida Jin, Haiping Du, Zhen Jiang, Weihua Li
Summary: The researchers have developed a liquid metal-doped polyvinyl alcohol hydrogel that exhibits ultra-high conductivity and excellent mechanical properties. The high conductivity is achieved through the self-sintering behavior of the liquid metal, while the impressive mechanical properties are attributed to the formation of polymer crystalline regions and polymer-tannic acid multiple hydrogen bonds.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Engineering, Mechanical
Lei Deng, Shuaishuai Sun, Qihao Wu, Ning Gong, Jiang Yang, Shiwu Zhang, Haiping Du, Weihua Li
Summary: This study develops a highly stable quasi-zero stiffness (QZS) vibration isolation system integrated with magnetorheological fluids (MRFs) to overcome the unstable problem of QZS systems and expand their application range.
NONLINEAR DYNAMICS
(2023)
Article
Physics, Multidisciplinary
Vladimir Sokolovski, Tongfei Tian, Jie Ding, Weihua Li
Summary: This study focused on the rheological measurements and normal compression tests of a shear thickening fluid (STF) below room temperature from -20 to 20 degrees C. The STF was composed of 20% fumed silica and 80% ethylene glycol by weight. Various tests were conducted on the STF, including temperature dependency tests, steady-state tests, oscillatory frequency sweep tests, oscillatory shear strain amplitude sweep tests, and normal compression tests. The results showed that temperature, frequency, and shear rate all played important roles in the performance of the STF. The equivalent normal stiffness of the STF could be increased by lowering the temperature or increasing the shear rate. A mathematical model was used to represent the viscosity of the STF within the tested temperature range.
Article
Engineering, Mechanical
Shiwei Liu, Gaoliang Peng, Zhixiong Li, Weihua Li, Lidong Sun
Summary: This paper presents a new elastic origami-inspired structure with quasi-zero-stiffness (QZS) characteristics for effective low-frequency vibration isolation. The mechanical model of the origami mechanism is established by integrating elastic joints with compression springs. The derived nonlinear stiffness characteristics contribute to a high-performance QZS isolator. The experimental results validate the effectiveness of the theoretical model and the advantages of the origami-inspired vibration isolation system in comparison with typical nonlinear passive isolators.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Automation & Control Systems
Xiangjun Xia, Donghong Ning, Yulin Liao, Pengfei Liu, Haiping Du, Weihua Li, Guijie Liu
Summary: This article proposes a novel multifunction electrically interconnected suspension (MFEIS) system that can reduce vibration and harvest energy at the same time. Two H-bridge circuits are used to control the energy flow. The energy flow and control procedures of each mode are studied, and two multiobjective control strategies are proposed to balance ride comfort and energy recovery performance.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2023)
Article
Automation & Control Systems
Wanli Liu, Zhixiong Li, Weihua Li, Paolo Gardoni, Haiping Du, Miguel Angel Sotelo
Summary: This article proposes a new method that integrates the double layer recurrent neural network (DLRNN) and multistate constrained Kalman filter (MSCKF) to online correct the LiDAR-IMU time delay errors. The proposed method significantly improves the efficiency and accuracy of the time delay error correction in a real-time manner. The experimental results demonstrate that the LiDAR-IMU time delay error can be accurately and quickly corrected, improving the positioning and navigation performance of the LiDAR-IMU system.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2023)
Article
Automation & Control Systems
Yulin Liao, Donghong Ning, Pengfei Liu, Haiping Du, Weihua Li
Summary: This article proposes an acceleration-measurement-based disturbance compensation control strategy for vehicles with electrically interconnected suspension (EIS). By introducing a disturbance observer, unknown disturbances are estimated using acceleration measurements, and the gains of the observer and H-infinity controller are obtained simultaneously using the linear matrix inequality method to simplify the implementation process. The control strategy utilizes vertical acceleration and angular acceleration to form a closed-loop feedback control, enhancing robustness.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
