Continuously enhancing human life increases the advances in technology. Flexible electronics compensate or even replace traditional rigid material-based electronic devices. They have very useful properties such as ductility, stretchability, ultra-thinness, etc. Flexible devices can be seamlessly mounted onto the human skin or other complex object surfaces. This helps connect our bodies to machines and to the environment. These devices are being widely applied for healthcare, human-machine-environment interfaces, energy, intelligent robots, the Internet of Things (IoT), etc. Therefore, these devices have been considered as next-generation smart electronics.

Flexible devices can be categorized. For instance, there are flexible electrodes, sensors, batteries, supercapacitors, and solar cells. Two strategies are employed to construct flexible electronic devices, including materials innovation and structural design. In particular, functional nanomaterials are considered indispensable parts of flexible electronics. In the past decade, we have witnessed the development of various functional nanomaterials, including nanoparticles, nanowires, nanosheets, and nanoporous materials. These nanomaterials can be applied as dopants, conductive interconnections, active sensing units, or performance-enhanced elements.

The aim of this Special Issue is to bring together original research and review articles discussing this research topic. Submissions can include the application of functional nanomaterials for wearable electronics, human-machine-environment interfaces, robotics, Internet of Things (IoT), artificial intelligence (AI), intelligent agriculture, and implantable electronics.

Potential topics include but are not limited to the following:

• Nanoparticles in flexible electronics
• Nanowires in flexible electronics
• Nanosheets in flexible electronics
• Nanoporous flexible electronics
• Hydrogels in flexible electronics
• Liquid metal in flexible electronics
• Polymers in flexible electronics
• Composites in flexible electronics