Abstract: Flexible sensors, a class of devices that can convert external mechanical or physical signals into changes in resistance, capacitance, or current, have developed rapidly since the concept was first proposed. Due to the special properties and naturally occurring excellent microstructures of biomaterials, it can provide more desirable properties to flexible devices. This paper systematically discusses the commonly used biomaterials for bio-based flexible devices in current research applications and their deployment in preparing flexible sensors with different mechanisms. According to the characteristics of other properties and application requirements of biomaterials, the mechanisms of their functional group properties, special microstructures, and bonding interactions in the context of various sensing applications are presented in detail. The practical application scenarios of biomaterial-based flexible devices are highlighted, including human-computer interactions, energy harvesting, wound healing, and related biomedical applications. Finally, this paper also reviews in detail the limitations of biobased materials in the construction of flexible devices and presents challenges and trends in the development of biobased flexible sensors, as well as to better explore the properties of biomaterials to ensure functional synergy within the composite materials.

Key words: Biomaterials, Flexible devices, Sensing properties, Bonding of groups, Electromechanical properties, Structural properties