Natural polyelectrolyte-based ultraflexible photoelectric synaptic transistors for hemispherical high-sensitive neuromorphic imaging system

Outstanding features of the human retina are its concave hemispherical geometry, high-sensitive image acquisition, and neuromorphic visual processing, which not only simplifies the optical complexity for the eye but also enhances imaging quality for the visual perception. However, the development of a high-performance bioinspired imaging system with these features is extremely challenging because of the restriction of its composing materials, device structures, and conventional imaging modules. Here, we present a novel hemispherical high-sensitive neuromorphic imaging system that leverages a natural acidic polyelectrolyte as dielectric layer in the photoelectric synaptic transistors. The devices have an extraordinary photosensitivity (~10 4 ) under a dim light condition (56 μW/cm 2 ) and the light-tunable neuromorphic characteristics, as well as a substrate-free and ultrathin (~475 nm) structure. These advantages enable our system to perform high-quality imaging like the human retina and highly simulate various functions of the human visual system, such as image enhancement and erasure, and visual preprocessing. A novel neuromorphic imaging system inspired by the human retina with the concave hemispherical geometry and ultrasensitive image acquisition, is implemented to simplify the optical complexity and enhance imaging quality. This can promote the current performances of advanced mobile imaging electronics, and could apply in the emerging visual prosthetics and artificial intelligence. • A hemispherical high-sensitive neuromorphic imaging system inspired by the functional and structural features of the human retina. • The devices possess an extraordinary photosensitivity (~10 4 ) under a dim light condition (56 μW/cm 2 ) by leverages a natural acidic polyelectrolyte. • The devices can intimately conform to 3D concave hemispherical surface due to substrate-free and ultrathin (~475 nm) structure. • The system can simulate various functions of the human visual system in terms of photoelectric synaptic plasticity. • The system could be of use in the next-generation visual prosthetics, artificial intelligence, and high-performance mobile imaging electronics.