be circumvented by exploiting an elementary mechanics that surface bending strain decreases linearly with a thickness of a substrate. For example, flexible substrates with a thicknesses of 10 µm experience peak surface strain of only 0.1% upon bending to the radius of curvature of 5 mm, and this strain remains well below the fracture limits of semiconductors (≈1%), metals (1-2%), and hard coatings (1-3%); indeed, the use of a substrate within a range below tens of micrometers enables comparable growth, resulting in high-performance durable flexible devices for epidermal, implantable, and wearable applications (Figure 1b). [10-20] On the other hand, the development of foldable electronics devices that have thicknesses of hundreds of micrometers is an emerging challenge. This highlights the ever-growing importance of the substrates strategically designed to reduce surface strain without thinning (Figure 1a right and 1b). However, it is not yet possible to measure nanoscale surface bending strain in real time: none of the currently available advanced methods fulfill all of the necessary spatial-temporal resolution, accuracy, precision, and a wide range of measurable materials. Electrical strain sensors including strain gauges exemplify the most common strain analytical method. [21-23] Although they provide surface bending strains of materials targeted in real time, their With the rapid development of flexible electronics and soft robotics, there is an emerging topic of preventing fracture in materials and devices integrated on largely bending film substrates of >100 µm thickness. The high demand for strategically reducing strain in bending materials requires a facile method that enables one to accurately and precisely analyze the surface bending strain in a wide variety of materials. This study proposes the surface-labeled grating method that is the fundamental and efficient technique for measuring surface bending strains merely by labeling a thin, soft grating onto various film substrates composed of flexible polymeric and rigid inorganic materials. The surface strain with a single-nanoscale (<1.0 nm) can be quantified in real time with no need of material information such as Poisson's ratio, Young's modulus, and film thickness. The fracture limit of a hard coating overlying flexible substrates is successfully determined by the accurate and precise quantification of surface bending strains. Furthermore, a multilayer film substrate with surface bending strain reduced by 50% prevents fractures of hard coatings and organic thin film transistors (OTFTs) since the strains remain below the fracture limit under large bending.
A highly periodic electrostatic potential, even though established in van der Waals bonded organic crystals, is essential for the realization of a coherent band electron system. While impurity doping is an effective chemical operation that can precisely tune the energy of an electronic system, it always faces an unavoidable difficulty in molecular crystals because the introduction of a relatively high density of dopants inevitably destroys the highly ordered molecular framework. In striking contrast, a versatile strategy is presented to create coherent 2D electronic carriers at the surface of organic semiconductor crystals with their precise molecular structures preserved perfectly. The formation of an assembly of redox‐active molecular dopants via a simple one‐shot solution process on a molecularly flat crystalline surface allows efficient chemical doping and results in a relatively high carrier density of 1013 cm−2 at room temperature. Structural and magnetotransport analyses comprehensively reveal that excellent carrier transport and piezoresistive effects can be obtained that are similar to those in bulk crystals.
This paper proposes a novel pipe inside a magnetic actuator that operates on the elastic energy of a vibration component excited by electromagnetic force. Flexible material such as rubber was used to support the actuator in the pipe and was used as a means of transferring elastic energy. The actuator is moved by the difference between forward and backward forces of support point of actuator. In the experiment, the actuator that was shielded by a thin acrylic hollow cylinder for movement inside a pipe with an inner diameter of 11 mm was prototyped. Characteristics of movement for the actuator were measured in air and water. The actuator could climb at 14.1 mm/s when pulling a load mass of 30 g. In the water, the speed of the actuator compared to the air was approximately 50 % by viscosity resistance of the water. In addition, a prototype of a new magnetic actuator combined with a memory alloy (SMA) wire and an electromagnetic vibration component was proposed and fabricated. In the actuator, the supporting force inside the pipe can be varied by the SMA wire. The speed of the actuator was measured in a pipe soiled with oil. In a pipe with a coefficient of friction of 0.28, it can pull vertically at a speed of 2 mm/s while generating a traction force of 0.088 N. Experimental results demonstrated that this actuator can be used in various environments such as atmospheric air, underwater, and piping with corroded parts. In the future, it is possible to observe the damaged condition inside the piping by mounting a micro CCD-camera on the actuator.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.