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Your search keyword '"Liu, Jingquan"' showing total 101 results
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101 results on '"Liu, Jingquan"'

12. Antiferroelectric Phase Evolution in Hf x Zr 1-x O 2 Thin Film Toward High Endurance of Non-Volatile Memory Devices.

Author

Chen, Danyang, Zhong, Shuman, Dong, Yulong, Cui, Tianning, Liu, Jingquan, Si, Mengwei, and Li, Xiuyan

Subjects
COMPUTER storage devices, THIN films, NONVOLATILE memory, ANTIFERROELECTRIC materials, RADARSAT satellites
Abstract

In this study, we experimentally and theoretically demonstrated a universal pathway of hysteresis evolution in polarization switching cycling in both antiferroelectric (AFE) and ferroelectric (FE) Hf xZr $_{\text {1-x}}\text{O}\,\,_{{2}}$ (HZO) thin films. AFE films can achieve sufficient remnant polarization and high endurance by engineering the evolution process of double hysteresis merge. Based on this, we propose a new strategy for realizing high-endurance AFE films in non-volatile memory devices. Additionally, a record high endurance >10 12 on 6 nm AFE HZO under full polarization switching conditions at 4.5 MV/cm and 1 MHz is achieved to demonstrate the potential of this strategy. [ABSTRACT FROM AUTHOR]

Published
2022
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19. Multifunctional Microelectrode for Low-Voltage Pulsed Field Ablation in Atrial Fibrillation.

Author

Xu, Mengfei, Hong, Wen, Song, Ziliang, Guo, Zhejun, Wang, Longchun, You, Minmin, Lin, Zude, Yang, Bin, Qin, Mu, and Liu, Jingquan

Subjects
ATRIAL fibrillation, ELECTROPORATION, MEDICAL balloons, FINITE element method, MINIMALLY invasive procedures, INDUCTIVE effect
Abstract

Pulsed field ablation is an emerging technique for the treatment of atrial fibrillation, and it can specifically damage cardiomyocytes without destroying surrounding tissues. However, current single-function ablation electrodes apply electric pulses at thousands of volts, which is potentially harmful to the heart. In this letter, we propose a multifunctional microelectrode for low-voltage pulsed field ablation and effect evaluation. By using finite element analysis and tests on potato tissues and in vivo experiments, we show that the soft microelectrode in multiplexed array format supports two orders of magnitude reduction in ablation voltage compared with the state of the art. Meanwhile, the electrode-tissue equivalent circuit before and after irreversible electroporation is established, and we find that the ablation effect could be evaluated by impedance. In the future, the microelectrode integrated with a medical balloon can be applied to minimally invasive surgery for improving the success rate of pulsed field ablation. [ABSTRACT FROM AUTHOR]

Published
2022
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20. An Ultrathin Low-Invasive Flexible Probe for Accurate Neural Stimulating.

Author

Guo, Zhejun, Wang, Longchun, Tu, Kejun, Xi, Ye, Hong, Wen, Wang, Xiaolin, Yang, Bin, Lin, Zude, and Liu, Jingquan

Subjects
FLEXIBLE structures, POLYETHYLENE glycol, NEUROLOGICAL research, DIAGNOSIS, NEUROLOGICAL disorders
Abstract

Neural probe plays an important role in neuroscience research and neurological diseases diagnosis. The flexible neural probes made by polymer emerging in recent years have been manifested more compliant and compatible with bio-tissues. However, the implantation of the flexible probe becomes another problem to be solved. In this letter, we propose a platinum black (Ptb) enhanced ultrathin flexible neural probe for accurate implantation. Benefiting from the anchoring structure on the flexible probe and the probe coupling with the shuttle by polyethylene glycol (PEG), reliable high-precision implantation has been demonstrated in agar model. Compared with traditional probe made with stiff shank, this flexible probe with anchoring structure is biocompatible and shows less immune reaction. In addition, the population spike (PS) was evoked successfully by biphasic stimulation in vivo. [ABSTRACT FROM AUTHOR]

Published
2022
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21. Thick Film Ultrasonic Micromotor Based on Chemical Mechanical Thinning and Polishing Process.

Author

Zhang, Pinbao, Niu, Jiaqi, Zhang, Xin, Mao, Shunming, Liu, Jingquan, and Yang, Bin

Subjects
THICK films, ULTRASONIC waves, ULTRASONIC motors, GRINDING & polishing, ULTRASONICS, STATORS, METAL pickling
Abstract

In this letter, a millimeter scale thick film rotating traveling wave ultrasonic motor based on chemical mechanical thinning and polishing process was proposed. The 30 $\mu \text{m}$ thick piezoelectric functional layer is fabricated to realize good compactness and high piezoelectric properties. The thickness and diameter of the stator are about 240 $\mu \text{m}$ and 4 mm, respectively. The vibration mode of the motor is B02 mode under the resonant frequency of 26.2 kHz. The motor can achieve stable bidirectional rotation under the excitation of four sinusoidal voltages. Moreover, when the excitation voltage is 50 $\text{V}_{\text {pp}}$ , the maximum speed can reach 766 rpm under the preload force of 686 $\mu \text{N}$. [ABSTRACT FROM AUTHOR]

Published
2022
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28. A Fully Flexible Hydrogel Electrode for Daily EEG Monitoring.

Author

Shen, Gencai, Gao, Kunpeng, Zhao, Nan, Wang, Zhuangzhuang, Jiang, Chunpeng, and Liu, Jingquan

Abstract

Electroencephalography (EEG) equipment and data analysis algorithms have made great progress in the field of brain-computer interfaces (BCIs). However, the development of EEG electrodes that directly contact with users is relatively slow, especially in daily EEG monitoring. The installation procedure of wet electrodes widely used in hospitals and clinics is complicated, largely limiting its application in the family. Herein, we report a fully flexible hydrogel electrode for daily EEG monitoring. The materials used in the electrode are all flexible, making it suitable for the curvature of the skin, convenient to install, and comfortable to wear. The addition of glycerol to the hydrogel enhanced its moisturizing performance, and the hydrogel still maintained a strong elasticity after being placed in the air for 90 days. The EEG signals of alpha oscillation during eyes closed were successfully collected, and the average coherence between hydrogel electrodes and Ag/AgCl wet electrodes reached 0.910. The prepared hydrogel electrode shows satisfactory performance, providing an effective strategy for daily EEG monitoring. [ABSTRACT FROM AUTHOR]

Published
2022
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41. Obtaining High SPL Piezoelectric MEMS Speaker via a Rigid-Flexible Vibration Coupling Mechanism.

Author

Wang, Qi, Yi, Zhiran, Ruan, Tao, Xu, Qingda, Yang, Bin, and Liu, Jingquan

Subjects
SOUND pressure, MICROELECTROMECHANICAL systems
Abstract

Among the main problems affecting the sound pressure level (SPL) of piezoelectric microelectromechanical systems (MEMS) speakers is that the membrane vibration displacement of those with sealed membranes is small, while those with unsealed membranes suffer from acoustic loss. Presented here is a high-SPL piezoelectric MEMS speaker via a rigid-flexible coupling mechanism, which can maintain large vibration displacement of the unsealed membranes without acoustic loss. The ingenious deposition of Parylene C on the upper surface before etching the back cavity is the key process forming the rigid–flexible-coupling sealed vibration membrane. Compared with that of the proposed speaker without the flexible sealed Parylene C at 2 V, the SPL generated by that with the rigid–flexible-coupling sealed vibration membrane is 3.0–26.1% higher, the frequency range of the speaker with the sealed membrane is widened from 250 Hz–20 kHz to the human hearing frequency range of 20 Hz–20 kHz for SPLs exceeding 59 dB, and a 101.2-dB SPL is obtained at the resonance frequency of 6.7 kHz. This simple strategy represents a significant step toward practical applications of piezoelectric MEMS speakers, given the wide frequency band, high SPL, and low power consumption. [2021-0041] [ABSTRACT FROM AUTHOR]

Published
2021
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