Fully Screen-Printed, Multicolor, and Stretchable Electroluminescent Displays for Epidermal Electronics

Abstract

A stretchable alternating current electroluminescent display seamlessly combines the light-emitting capabilities with mechanical compliance, which offers exciting opportunities for applications in wearable gadgets, soft robots, and fashion designs. The widespread adaption to deformable forms of optoelectronics is currently impeded by the tedious and labor-intensive fabrication process. This study reports an efficient and scalable procedure to create a fully screen-printed, multicolor, and stretchable electroluminescent display. The as-prepared device exhibits excellent deformability and low-voltage operation. The practical implementation is demonstrated by creating a wearable sound-synchronized sensing system with an epidermal display responsive to the rhythm of music. The ink formulation and printing procedure developed here pave the way for convenient fabrication of stretchable electronic devices.

Structures and Materials in Stretchable Electroluminescent Devices

“…Conductive materials can also form networks embedded in elastomers. [10,61,77,92] Like the structure of conductive thin layers on elastomer surface, the optical and mechanical properties of embedded structure are dominated by the conductive networks and the matrix, respectively. In addition, embedding conductive network in an elastomeric substrate can significantly reduce surface roughness, which is critical for OLEDs.…”

“…Nowadays, a variety of conductive materials have been used in these structures, including metallic/carbon nanomaterials, [ 70 ] conducting polymers, [ 71 ] ionic conductors, [ 72 ] thin metal films, [ 73 ] etc. Polymers like silicone, [ 74 ] chitosan, [ 75 ] PAM hydrogels, [ 76 ] PUs, [ 68 ] and poly(styrene‐b‐(ethylene/butylene)‐b‐styrene) (SEBS) [ 77 ] have been utilized as matrices of electrodes. In this section, these three typical structures as well as corresponding materials are discussed in detail.…”

Designable Integration of Silicide Nanowire Springs as Ultra‐Compact and Stretchable Electronic Interconnections

“…Stretchable electronics with compliant mechanical deformability and electrical reliability [ 1 ] have been the focus of intense research over the past decades, which are indispensable features required in the fields of medical devices, [ 2 ] displays, [ 3,4 ] sensors, [ 5–10 ] wearable devices, [ 11–13 ] memory, [ 14,15 ] and electronic skins. [ 16–18 ] While the active electronic logic, sensor or light emission units can be safely constructed and protected upon discrete rigid‐islands, distributed on the soft polymer (such as, PDMS) substrate as depicted in Figure a, the conductive interconnections among the islands must be highly elastic and robust to sustain or dissipate large stretching strain.…”

A Printable and Conductive Yield-Stress Fluid as an Ultrastretchable Transparent Conductor

“…The degradations of optoelectronic performances upon tensile deformations are ascribed to the sliding between silver nanowires and damages to internanowire junctions [ 19 , 20 ]. Sliver nanowires with high area loading and plenty of junctions are often employed to achieve improved stretchability at the price of reduced optical transmittance [ 19 – 21 ]. In addition, the conductive properties of these electrodes typically show rapid deteriorations under biaxial tensions unless carefully engineered microstructures are employed [ 22 , 23 ].…”