Efficient electromechanical conversion regulation to enhance the sensitivity of flexible strain sensors

Flexible strain sensors have emerged as fundamental components in intelligent sensing systems, attributed to their lightweight, wearability, stretchability and responsiveness to strain. Traditional flexible strain sensors are plagued by inadequate interface bonding strength and dispersed distribution of stress fields. These factors result in the diminished electromechanical conversion efficiency, thereby significantly hindering the sensitivity of micro strain monitoring in intricate configurations. In response to this challenge, this review proposes theoretical framework for the collaborative regulation of interface and structures, with the objective of facilitating efficient electromechanical conversion. The interface strengthening mechanism and regulation methods of localized and gradient stress fields have been systematically elucidated, thereby uncovering the mechanism by which stress transfer induces electrical signal mutation in polymer composite materials. Simultaneously, it is essential to elucidate the trajectory of technological advancement from single modal responses to multimodal perception, ultimately to the integration of functional systems at the comprehensive level. Finally, this study will explore the critical scientific challenges related to micro strain sensing limitation and programmable sensitivity regulation. The objective of this investigation is to promote the advancement of sophisticated intelligent sensing systems that are marked by deep integration of interactions among humans, machines and objects.