Recent years have witnessed significant research efforts in flexible organic and amorphous-metal-oxide analogue electronics, in view of its formidable potential for applications such as smart sensor systems. This Element provides a comprehensive overview of this growing research area. After discussing the properties of organic and amorphous-metal-oxide technologies relevant to analogue circuits, this Element focuses on their application to two key circuit blocks: amplifiers and analogue-to-digital converters. The Element thus provides a fresh look at the evolution and immediate opportunities of the field, and identifies the remaining challenges for these technologies to become the platform of choice for flexible analogue electronics.

Recent years have witnessed significant research efforts in flexible organic and amorphous-metal-oxide analogue electronics, in view of its formidable potential for applications such as smart sensor systems. This Element provides a comprehensive overview of this growing research area. After discussing the properties of organic and amorphous-metal-oxide technologies relevant to analogue circuits, this Element focuses on their application to two key circuit blocks: amplifiers and analogue-to-digital converters. The Element thus provides a fresh look at the evolution and immediate opportunities of the field, and identifies the remaining challenges for these technologies to become the platform of choice for flexible analogue electronics.

Semiconducting nanostructures such as nanowires (NWs) have been used as building blocks for various types of sensors, energy storage and generation devices, electronic devices and for new manufacturing methods involving printed NWs. The response of these sensing/energy/electronic components and the new fabrication methods depends very much on the quality of NWs and for this reason it is important to understand the growth mechanism of 1D semiconducting nanostructures. This is also important to understand the compatibility of NW growth steps and tools used in the process with these unconventional substrates such as plastic that are used in flexible and large area electronics. Therefore, this Element presents at length discussion about the growth mechanisms, growth conditions and the tools used for the synthesis of NWs. Although NWs from Si, ZnO and carbon nanotubes (CNTs) are included, the discussion is generic and relevant to several other types of NWs as well as heterostructures.

Electronic skins are critical for many applications in human-machine-environment interactions. Tactile sensitivity over large areas can be especially applied to prosthetics. Moreover, the potential for wearables, interactive surfaces, and human robotics have propelled research in this area. In this Element, we provide an account and directional atlas of the progress in materials and devices for electronic skins, in the context of sensing principles and skin-like features. Additionally, we give an overview of essential electronic circuits and systems used in large-area tactile sensor arrays. Finally, we present the challenges and provide perspectives on future developments.

Stretchable electronics is one of the transformative pillars of future flexible electronics. As a result, the research on new passive and active materials, novel designs, and engineering approaches has attracted significant interest. Recent studies have highlighted the importance of new approaches that enable the integration of high-performance materials, including, organic and inorganic compounds, carbon-based and layered materials, and composites to serve as conductors, semiconductors or insulators, with the ability to accommodate electronics on stretchable substrates. This Element presents a discussion about the strategies that have been developed for obtaining stretchable systems, with a focus on various stretchable geometries to achieve strain invariant electrical response, and summarises the recent advances in terms of material research, various integration techniques of high-performance electronics. In addition, some of the applications, challenges and opportunities associated with the development of stretchable electronics are discussed.

Hybrid Systems-in-Foil (HySiF) is a concept that extends the potential of conventional More-than-More Systems-in/on-Package (SiPs and SoPs) to the flexible electronics world. In HySiF, an economical implementation of flexible electronic systems is possible by integrating a minimum number of embedded silicon chips and a maximum number of on-foil components. Here, the complementary characteristics of CMOS SoCs and larger area organic and printed electronics are combined in a HySiF-compatible polymeric substrate. Within the HySiF scope, the fabrication process steps and the integration design rules with all the accompanying boundary conditions concerning material compatibility, surface properties, and thermal budget, are defined. This Element serves as an introduction to the HySiF concept. A summary of recent ultra-thin chip fabrication and flexible packaging techniques is provided. Several bendable electronic components are presented demonstrating the benefits of HySiF. Finally, prototypes of flexible wireless sensor systems that adopt the HySiF concept are demonstrated.

Advanced nanostructured materials such as organic and inorganic micro/nanostructures are excellent building blocks for electronics, optoelectronics, sensing, and photovoltaics because of their high-crystallinity, long aspect-ratio, high surface-to-volume ratio, and low dimensionality. However, their assembly over large areas and integration in functional circuits are a matter of intensive investigation. This Element provides detailed description of various technologies to realize micro/nanostructures based large-area electronics (LAE) devices on rigid or flexible/stretchable substrates. The first section of this Element provides an introduction to the state-of-the-art integration techniques used to fabricate LAE devices based on different kind of micro/nanostructures. The second section describes inorganic and organic micro/nanostructures, including most common and promising synthesis procedures. In the third section,different techniques are explained that have great potential for integration of micro/nanostructures over large areas. Finally, the fourth section summarizes important remarks about LAE devices based on micro/nanostructures, and future directions.