Mechanics of Strain-limiting wrinkled kirigami for flexible devices: High flexibility, stretchability and compressibility

2022 ◽  
Vol 238 ◽  
pp. 111382
Author(s):  
Yafei Wang ◽  
Changguo Wang
Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 580 ◽  
Author(s):  
Fenlan Xu ◽  
Xiuyan Li ◽  
Yue Shi ◽  
Luhai Li ◽  
Wei Wang ◽  
...  

Flexible pressure sensors are attracting great interest from researchers and are widely applied in various new electronic equipment because of their distinct characteristics with high flexibility, high sensitivity, and light weight; examples include electronic skin (E-skin) and wearable flexible sensing devices. This review summarizes the research progress of flexible pressure sensors, including three kinds of transduction mechanisms and their respective research developments, and applications in the fields of E-skin and wearable devices. Furthermore, the challenges and development trends of E-skin and wearable flexible sensors are also briefly discussed. Challenges of developing high extensibility, high sensitivity, and flexible multi-function equipment still exist at present. Exploring new sensing mechanisms, seeking new functional materials, and developing novel integration technology of flexible devices will be the key directions in the sensors field in future.


1992 ◽  
Author(s):  
P. FRAISE ◽  
B. COULOMB ◽  
A. DARBANDI ◽  
R. LENORMAND ◽  
D. RENE ◽  
...  

Author(s):  
Jie Zhu ◽  
Soo Sien Seah ◽  
Irene Tee ◽  
Bing Hai Liu ◽  
Eddie Er ◽  
...  

Abstract In this paper, we describe automated FIB for TEM sample preparation using iFast software on a Helios 450HP dual-beam system. A robust iFast automation recipe needs to consider as many variables as possible in order to ensure consistent sample quality and high success rate. Variations mainly come from samples of different materials, structures, surface patterns, surface topography and surface charging. The recipe also needs to be user-friendly and provide high flexibility by allowing users to choose preferable working parameters for specific types of samples, such as: grounding, protective layer coating, milling steps, and final TEM lamella thickness/width. In addition to the iFast recipe, other practical factors affecting automation success rate are also discussed and highlighted.


2020 ◽  
Vol 16 ◽  
Author(s):  
Muhammad Bilal Tahir ◽  
Aleena Shoukat ◽  
Tahir Iqbal ◽  
Asma Ayub ◽  
Saff-e Awal ◽  
...  

: The field of nanosensors has been gaining a lot of attention due to its properties such as mechanical and electrical ever since its first discovery by Dr. Wolter and first mechanical sensor in 1994. The rapidly growing demand of nanosensors has become profitable for a multidisciplinary approach in designing and fabrication of materials and strategies for potential applications. Frequent stimulating advancements are being suggested and established in recent years and thus heading towards multiple applications including food safety, healthcare, environmental monitoring, and biomedical research. Nanofabrication being an efficient method has been used in different industries like medical pharmaceutical for their complex functional geometry at a lower scale. These nanofabrications apply through different methods. There are five most commonly known methods which are frequently used, including top-down lithography, molecular self-assembly, bottom-up assembly, heat and pull method for fabrication of biosensors, etching for fabrication of nanosensors etc. Nanofabrication help at the nanoscale to design and work with small models. But these models due to their small size and being sensitive need more care for use as well as more training and experience to do work with. All methods used for nanofabrication are good and helpful. But more preferred is molecular self-assembly as it is helpful in mass production. Nanofabrication has become an emerging and developing field and it assumed that in near future our world is known by the new devices of nanofabrication.


Author(s):  
Kai Guo ◽  
Sitong Liu ◽  
Haoming Tu ◽  
Zhikun Wang ◽  
Liang Chen ◽  
...  

Crown ethers could serve as hosts to selectively incorporate various guest atoms or molecules within the macrocycles. However, the high flexibility of crown ether molecules limits their applications in areas...


2021 ◽  
Vol 18 (1) ◽  
pp. 40-54
Author(s):  
Zhengwei Wu ◽  
Yizhou Shen ◽  
Jie Tao ◽  
Zhenfeng Jia ◽  
Haifeng Chen ◽  
...  

Author(s):  
Xiuwei Sun ◽  
Shumei Liu ◽  
Qingyin Wu ◽  
Shan Zhang ◽  
Hong-Rui Tian ◽  
...  

Polyethyleneimine (PEI) is expected to become a new type of proton conduction booster due to its high density amine and extremely high flexibility. Herein, a nanofiber membrane (eHPW-PEI) composed of...


2015 ◽  
Vol 2 (3-4) ◽  
pp. 201-205
Author(s):  
Igor Ille ◽  
Sebastian Mojrzisch ◽  
Jens Twiefel

Abstract Ultrasonic actuators are used for a wide field of applications. The vibration energy can be used to realize many processes like ultrasonic welding or bonding. Furthermore there are many processes which run more efficient and faster combined with ultrasonic vibration like ultrasonic-assisted turning or drilling. Piezoelectric transducers are the main part of those applications. Most of the applications have a time-variant load behavior and need an amplitude feedback control to guarantee a stable process. To ensure correct function tests of the feedback control systems have to be done. In this case the processes have to be executed in association with a high number of cycles. To emulate the behavior of the environment the automotive and aerospace industries use hardware in the loop systems since a long time but there is no such a method for ultrasonic systems. This paper presents a method to realize high dynamic load emulation for different ultrasonic applications. Using a piezoelectric transformer it is possible to reproduce load curves by active damping on the secondary side of the transformer using a current proportional digital feedback circuit. A theoretical and experimental study of hardware in the loop system for ultrasonic applications is given by this paper. The present system allows testing a wide field of feedback control algorithms with high flexibility and a high number of cycles by utilization of low-cost components. This proceeding decreases design periods in association with feedback control.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Atiqur Rahman ◽  
Mohammad Tariqul Islam ◽  
Mandeep Singh Jit Singh ◽  
Md Samsuzzaman ◽  
Muhammad E. H. Chowdhury

AbstractIn this article, we propose SNG (single negative) metamaterial fabricated on Mg–Zn ferrite-based flexible microwave composites. Firstly, the flexible composites are synthesized by the sol-gel method having four different molecular compositions of MgxZn(1−x)Fe2O4, which are denoted as Mg20, Mg40, Mg60, and Mg80. The structural, morphological, and microwave properties of the synthesized flexible composites are analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and conventional dielectric assessment kit (DAK) to justify their possible application as dielectric substrate at microwave frequency regime. Thus the average grain size is found from 20 to 24 nm, and the dielectric constants are 6.01, 5.10, 4.19, and 3.28, as well as loss tangents, are 0.002, 0.004, 0.006, and 0.008 for the prepared Mg–Zn ferrites, i.e., Mg20, Mg40, Mg60, and Mg80 respectively. Besides, the prepared low-cost Mg–Zn ferrite composites exhibit high flexibility and lightweight, which makes them a potential candidate as a metamaterial substrate. Furthermore, a single negative (SNG) metamaterial unit cell is fabricated on the prepared, flexible microwave composites, and their essential electromagnetic behaviors are observed. Very good effective medium ratios (EMR) vales are obtained from 14.65 to 18.47, which ensure the compactness of the fabricated prototypes with a physical dimension of 8 × 6.5 mm2. Also, the proposed materials have shown better performances comparing with conventional FR4 and RO4533 materials, and they have covered S-, C-, X-, Ku-, and K-band of microwave frequency region. Thus, the prepared, flexible SNG metamaterials on MgxZn(1−x)Fe2O4 composites are suitable for microwave and flexible technologies.


2021 ◽  
Vol 5 (4) ◽  
pp. 110
Author(s):  
Flaminio Sales ◽  
Andrews Souza ◽  
Ronaldo Ariati ◽  
Verônica Noronha ◽  
Elder Giovanetti ◽  
...  

Polydimethylsiloxane (PDMS) is a polymer that has attracted the attention of researchers due to its unique properties such as transparency, biocompatibility, high flexibility, and physical and chemical stability. In addition, PDMS modification and combination with other materials can expand its range of applications. For instance, the ability to perform superhydrophobic coating allows for the manufacture of lenses. However, many of these processes are complex and expensive. One of the most promising modifications, which consists of the development of an interchangeable coating, capable of changing its optical characteristics according to some stimuli, has been underexplored. Thus, we report an experimental study of the mechanical and optical properties and wettability of pure PDMS and of two PDMS composites with the addition of 1% paraffin or beeswax using a gravity casting process. The composites’ tensile strength and hardness were lower when compared with pure PDMS. However, the contact angle was increased, reaching the highest values when using the paraffin additive. Additionally, these composites have shown interesting results for the spectrophotometry tests, i.e., the material changed its optical characteristics when heated, going from opaque at room temperature to transparent, with transmittance around 75%, at 70 °C. As a result, these materials have great potential for use in smart devices, such as sensors, due to its ability to change its transparency at high temperatures.


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