ADVANCED MATERIALS
·
2021
·Vol. 34
·期 9
·2107840
·
IF 30.849
Yunpeng Wang,Jiahao Sun,Wei Liao,Zhongqiang Yang
Untethered twist fibers do not require end-anchoring structures to hold their twist orientation and offer simple designs and convenient operation. The reversible responsiveness of these fibers allows them to generate torque and rotational deformation continuously upon the application of external stimuli. The fibers therefore have potential in rotating microengines. In practical applications, high torque and rotational deformation are desirable to meet work capacity requirements. However, the simultaneous endowment of reversible responsiveness and high rotational performance to untethered twist fibers remains a challenge. In this study, a liquid crystal elastomer twist fiber (LCETF) is designed and developed with a fixed twisting alignment of mesogens to provide untethered and reversible responsiveness. Outstanding rotational performance can be achieved when the mesogenic orientation is disrupted through heat triggering. Owing to the significant intrinsic contractile ratio of the LCE material, the rotational deformation of the LCETF can reach 243.6° mm −1 . More importantly, the specific torque can reach 10.1 N m kg −1 , which exceeds previously reported values. In addition, the LCETF can be exploited in a rotating microengine to convert heat into electricity with an induction voltage as high as 9.4 V. This work broadens the applications of LCEs for energy harvesters, micromachines, and soft robots.
研究领域:
材料科学
·
能源技术
·
机器人学
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2024
·Vol. 14
·期 1
·1-11
·
IF 3.8
Ren Jia,Cai Haopeng,Zhao Gaiqing,Xu Zhuang,Wang Xiaobo
The effects of shear degradation on the microstructures and properties of grease were investigated using a planetary ball mill to simulate a bearing shear zone on grease. The microstructure, cone penetration, colloidal stability, rheological properties noise properties, water washout characteristics and low-temperature torque of lithium grease were characterized. The microstructure of the initial lithium grease is a three-dimensional network structure formed by the uniform fibers. The entanglement level is high. As the ball milling shear time increases, the network structure of lithium grease is destroyed and the fibers are sheared to become short. Eventually all of them become short fibers. The performance test of lithium grease reveal that the cone penetration increases, colloidal stability, structural strength, noise properties, water washout characteristics of lithium grease gradually decreased with the increase of ball milling shear time. Additionally, the low-temperature starting torque and running torque of the grease gradually decrease. This phenomenon occurs due to changes in the microstructure of lithium grease. The shear degradation of lithium grease was mainly divided into two stages: the rapid stage was the destruction of the thickener network structure and the fibers being shortened by shearing. The slow stage was the process in which short fibers were sheared into shorter fibers.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Science Advances
·
2023
·Vol. 9
·期 49
·
IF 13.6
Chao Yun,Haoran Guo,Zhongchong Lin,Licong Peng,Zhongyu Liang,Miao Meng,Biao Zhang,Zijing Zhao,Leran Wang,Yifei Ma,Yajing Liu,Weiwei Li,Shuai Ning,Yanglong Hou,Jinbo Yang,Zhaochu Luo
The discovery of magnetism in van der Waals (vdW) materials has established unique building blocks for the research of emergent spintronic phenomena. In particular, owing to their intrinsically clean surface without dangling bonds, the vdW magnets hold the potential to construct a superior interface that allows for efficient electrical manipulation of magnetism. Despite several attempts in this direction, it usually requires a cryogenic condition and the assistance of external magnetic fields, which is detrimental to the real application. Here, we fabricate heterostructures based on Fe3GaTe2 flakes that have room-temperature ferromagnetism with excellent perpendicular magnetic anisotropy. The current-driven nonreciprocal modulation of coercive fields reveals a high spin-torque efficiency in the Fe3GaTe2/Pt heterostructures, which further leads to a full magnetization switching by current. Moreover, we demonstrate the field-free magnetization switching resulting from out-of-plane polarized spin currents by asymmetric geometry design. Our work could expedite the development of efficient vdW spintronic logic, memory, and neuromorphic computing devices.
研究领域:
自旋电子学
·
材料科学
·
凝聚态物理
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·Vol. 36
·期 24
·2312655
·
IF 27.4
Jinsheng Zhao,Chen Xin,Jiaqi Zhu,Neng Xia,Bo Hao,Xurui Liu,Yu Tan,Shihao Yang,Xin Wang,Junnan Xue,Qinglong Wang,Haojian Lu,Li Zhang
Multimodal and controllable locomotion in complex terrain is of great importance for practical applications of insect-scale robots. Robust locomotion plays a particularly critical role. In this study, a locomotion mechanism for magnetic robots based on asymmetrical friction effect induced by magnetic torque is revealed and defined. The defined mechanism overcomes the design constraints imposed by both robot and substrate structures, enabling the realization of multimodal locomotion on complex terrains. Drawing inspiration from human walking and running locomotion, a biped robot based on the mechanism is proposed, which not only exhibits rapid locomotion across substrates with varying friction coefficients but also achieves precise locomotion along patterned trajectories through programmed controlling. Furthermore, apart from its exceptional locomotive capabilities, the biped robot demonstrates remarkable robustness in terms of load-carrying and weight-bearing performance. The presented locomotion and mechanism herein introduce a novel concept for designing magnetic robots while offering extensive possibilities for practical applications in insect-scale robotics.
研究领域:
机器人学
·
生物力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
·
2022
·Vol. 28
·期 4
·719-725
·
IF 2.297
Deling Li,Congcong Luo,Bing Yao,Yue Ding,Jizhen Ren
Lanthanum complex with curcumin (La L 2 )/Ca-Zn composite stabilizer was prepared using La L 2 and Ca-Zn stabilizer, in which Ca-Zn stabilizer was obtained from calcium stearate and zinc stearate at their mass ratio of 5:1. The rheological properties and dynamic thermal stability of polyvinyl chloride (PVC) stabilized by La L 2 /Ca-Zn composite stabilizers were estimated through a torque rheometer. The degraded fragments obtained from the torque experiments were measured by Fourier-transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV-vis) spectroscopy. La L 2 had an effective synergistic effect with Ca-Zn stabilizer. Compared with La L 2 , La L 2 /Ca-Zn composite stabilizer could more significantly improve the rheological properties and dynamic thermal stability of PVC. An optimal synergistic effect could be observed when the mass ratio of La L 2 with Ca-Zn stabilizer was about 8:2, in which the plasticizing torque and equilibrium torque of PVC was 33.3 N m and 22.5 N m, respectively, and its dynamic thermal stabilizing time was 25.1 min. The possible thermal stability mechanism of La L 2 /Ca-Zn composite stabilizer for PVC was suggested based on the evaluation of FTIR spectroscopy and UV-vis spectroscopy.
研究领域:
材料科学
·
高分子科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Ying Chen,Qiang Zhang,Jian Shen,Zhiran Liu,Xiaoyu Cui,Li Ma,Yuanyi Zheng,Longchen Wang,Tao Ying
Chemotherapy is the main clinical treatment for ovarian cancer, but still faces challenges of low drug targeting efficiency and insufficient drug permeability. Drug-loaded nanoparticle collectives, which are actuated by magnetic field, could be targeted to a designated location and achieve targeted drug delivery. In this work, we report a strategy that utilizes magnetic mesoporous silica nanoparticles loaded with cis -diaminodichloroplatinum (Fe 3 O 4 @SiO 2 -CDDP) for targeted delivery of chemotherapeutic drugs and enhances penetration into deep tumors. The Fe 3 O 4 @SiO 2 -CDDP collectives actively moved to the target tumor site, and this movement was regulated by a magnetic actuation system. Under the action of a torque-force hybrid magnetic field (TFMF), Fe 3 O 4 @SiO 2 -CDDP could further penetrate into the interior of tumors and achieve pH-responsive drug release in the tumor environment. The feasibility of this strategy was verified in three-dimensional cell spheres in vitro and in a tumor-bearing mouse model in vivo. This magnetically actuated nanoparticle collectives enhanced drug penetration strategy provides a new paradigm for targeted drug delivery and potentiated tumor therapy.
研究领域:
肿瘤学
·
纳米技术
·
药学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
·
2023
·Vol. 33
·期 5
·1219-1233
·
IF 4
Zhang Qian,Qiao Qikai,Wang Zihao,Liu Yuanyuan,Pei Zhen,Guo Jiandong,Fei Pengfei,Zhang Aiqin,Jia Husheng,Xu Bingshe
In order to solve the problem of poor compatibility between modified-ZIF-8 nanoparticles and mask matrix polypropylene (PP) and melt-blown materials, in this work, PP based modified-ZIF-8 antibacterial masterbatch was prepared employing surface modification and torque blending method. IR, SEM, XRD, XPS, DSC results confirm that the antibacterial masterbatch maintains the chemical and crystal structure of modified-ZIF-8 and the thermal stability of PP. Photocatalytic performance indicates that the antibacterial masterbatch basically maintains the photoresponse range of modified-ZIF-8, has narrower band gap and the superior photocatalytic performance than that of modified-ZIF-8. The photocatalytic antibacterial mechanism of ·O 2 − and h + as antibacterial active species is revealed according to the energy band structure and free radical capture experiment. The photocatalytic antibacterial activity of the antibacterial masterbatch against Staphylococcus aureus and Escherichia coli under different dosage holds that the relationship between antibacterial rate and antibacterial agent concentration conforms to Beta distribution, demonstrating second-order kinetic behavior. The antibacterial properties reach the maximum when the loading of modified-ZIF-8 is 2% of the total weight of PP and melt-blown materials. S. aureus and E. coli could be completely killed when the simulated sunlight is irradiated for 30 min. These results indicate that PP based modified-ZIF-8 antibacterial masterbatch has potential application in photocatalytic antibacterial masks.
研究领域:
材料科学
·
化学工程
·
纳米技术
·
光催化
·
抗菌材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）