Next-generation stretchable optoelectronics require functional electric conductors with mechanical stretchability and optical transparency. We present a new class of highly stretchable and transparent conductors based on silver nanowire (AgNW) percolation microgrids embedded in an elastomeric substrate. These are prepared by simple spray-coating and subsequent adhesive-tape-assisted contact-removal of the AgNWs. The synergetic combination of the percolated NWs and regular micro-grid geometry in an integrated form makes it possible to achieve uniform, reproducible, and predictable performance of the resulting AgNW microgrids and ensure good stretchability. The fabricated device shows superior optoelectronic performance with a sheet resistance of 26.1 Ω/sq and an optical transmittance of 85.8 %. In addition, the device can reversibly accommodate various mechanical deformations, such as stretching, bending, and twisting. Graphical AbstractA new class of highly stretchable and transparent conductor based on silver nanowire (AgNW) percolation micro-grids prepared by spray-coating and subsequent adhesive-tape-assisted contact removal of AgNWs is presented.

A one-step hybrid bending/diffusion bonding process (HB/DBP) was developed for application to Ti-6Al-4V sheets to effectively improve buy-to-fly (BTF) ratio of aircraft parts, integrating sequential diffusion bonding followed by a bending process. The resulting bonding characteristics of these titanium alloy sheets were analyzed. Microstructural analysis and mechanical lap shear tests were performed to estimate the bonding quality. Additionally, bonding ratio, thickness strain, and shear strength were evaluated in relation to pressure under increasing temperature. When the applied pressure was lower than 0.5 MPa, early failure occurred at the joint of the specimens. However, when high pressure was applied, early failure occurred near the joint. To discuss the phenomenon, time-dependent viscoplastic material properties were characterized, and a numerical simulation analysis was performed. Viscoplastic deformation was observed around the bending area, which caused weakness around the bond under high-pressure conditions. A prototype of a Y-shaped heat shield was manufactured and the buy-to-fly ratio was effectively improved using the newly developed process. This study demonstrates the potential of applying the developed process for producing aircraft parts and the importance of viscoplastic behavior for the analysis of final product reliability.

A simple convenient way of forming a selective patterning on a single nanowire was demonstrated by using a conventional optical microscope. The fine resolution could reach approximately 5 i m, which is enough to define electrode patterns on a single nanowire in a two-probe configuration. The photolithographic processes were carried out under the microscope with photoresist-coated substrate deposited by nanowires. Through the image capture and a proper configuration of the various home-made photomasks could produce a selective patterning on an individual nanowire successfully. Current-voltage characteristics of an individual GaN single nanowire were measured as a demonstration.