Take a fresh look at the evolution and immediate opportunities of flexible organic and amorphous-metal-oxide analogue electronics.With a comprehensive overview of flexible organic and amorphous-metal-oxide analogue electronics, take a fresh look at the evolution and immediate opportunities of the field.With a comprehensive overview of flexible organic and amorphous-metal-oxide analogue electronics, take a fresh look at the evolution and immediate opportunities of the field.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.1. Introduction; 2. Organic and amorphous-metal-oxide thin-film transistors; 3. Flexible analogue amplifiers; 4. Circuit techniques and architectures for analogue-to-digital converters; 5. Conclusions; 6. References.