The present and future of the flexible hybrid epidermal electronic system

Research on the flexible hybrid epidermal electronic system (FHEES) has attracted considerable attention due to its potential applications in human-machine interaction and healthcare. However, the heterogeneous integration of soft and stiff components makes balancing comfort and performance in designing and implementing FHEESs challenging. A new study, published in Research, reviews multimodal FHEESs in two types: all-in-one and assembled, highlighting the design challenge with different heterogeneous integration strategies.

Unlike previous reviews on flexible electronics, the paper, published by scientists from Tsinghua University focuses on system-level design and application of multimodal FHEESs. Multimodal FHEESs are first introduced in two types: all-in-one and assembled. All-in-one multimodal FHEESs adopt a stacked soft and stiff integrated structure, which is generally composed of flexible components near the skin, flexible substrates in the middle layer, stiff components in the top layer, and soft packaging. For assembled multimodal FHEESs, heterogeneous (soft and stiff modules) separation integration technology is used to avoid direct contact between flexible and stiff components. The difference in structure determines their applicable fields and respective weaknesses. As Tian-ling Ren, corresponding author of the study states, 'At present, all-in-one multimodal FHEESs are the most extensively studied and widely used flexible electronic systems. Still, the assembled multimodal FHEES is becoming an emerging trend.'

After summarizing the design strategy and potential applications of multimodal FHEESs, this article provides noteworthy development directions for research institutions and industry. As the paper states in the discussion section, 'biomimetic multimodal epidermal electronic systems', 'human-machine fusion systems', 'conductor and semiconductor elastic materials', 'manufacturing processes', 'self-power technology', and 'collaboration with machine learning/artificial intelligence' will dominate the future development of multimodal FHEESs. 'It should be emphasized that enabling FHEESs to benefit users more quickly requires close collaboration between academia and industry, which is also one of the original intentions of this paper from the system architecture perspective.' The authors hope that, the advent of multimodal FHEESs will revolutionize healthcare and human-machine interaction. Daily and personalized medical and human-machine interaction FHEES devices will alleviate medical resource scarcity and improve people's information processing capabilities.