Fig. 4

Key progresses and innovations in processes and materials. a The ideal properties required for soft substrates and representative applications in nervous system (reprinted with permission⁵². Copyright 2022, Springer Nature)⁵², body surface¹³, and gastrointestinal tract (reprinted with permission⁴³ under Creative Common CC BY license. Copyright 2023, American Association for the Advancement of Science)⁴³. b Soft active materials, including metal thin films (the left image is reprinted with permission⁵⁷. Copyright 2023, Springer Nature. The right image is reprinted with permission⁸⁵. Copyright 2021, John Wiley & Sons)^57,85, liquid metals (reprinted with permission⁸⁶. Copyright 2023, American Association for the Advancement of Science)^86,87,171, and conductive polymer materials (reprinted with permission⁸⁹. Copyright 2023, Springer Nature)⁸⁹, along with their associated fabrication processes such as spin coating, 3D printing, screen printing, inkjet printing, dispensing, and photolithography. c Soft emissive component including Micro-LED³¹ and OLED (reprinted with permission⁶⁰. Copyright 2022, Springer Nature)⁶⁰ (reprinted with permission¹⁰⁵. Copyright 2020, Springer Nature). d Soft encapsulation: hybrid organic/inorganic multilayer⁶⁹. e Heat dissipation design: flexible thermal materials, external control module^72,73, boron nitride nanoseed structure⁷⁴, and microchannels⁷⁷ for enhanced heat management. (reprinted with permission⁷⁴ under Creative Common CC BY license. Copyright 2020, Springer Nature) f Power supply including soft battery (the middle image is reprinted with permission¹²² under Creative Common CC BY license. Copyright 2024, Springer Nature. The right image is reprinted with permission¹⁴⁸. Copyright 2022, Springer Nature)^120,121,122 wireless power supply^{123,124,125,126} (the image for RF antenna is reprinted with permission⁷⁷. Copyright 2020, Springer Nature. The image for Infrared light is reprinted with permission¹²⁵. Copyright 2018, National Academy of Sciences). Figure 4, created with BioRender.com, released under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International license