In-memory sensing and computing devices integrate the functionalities of sensors, memory, and processors, offering advantages such as low power consumption, high bandwidth, and zero latency, making them particularly suitable for simulating synaptic behavior in biological neural networks. As the pace of digital transformation accelerates, the demand for efficient information processing technologies is increasing, and in-memory sensing and computing devices show great potential in AI, machine learning, and edge computing. In recent years, with the continuous advancement of infrared detector technology, infrared in-memory sensing and computing devices have also seen new opportunities for development. This article reviews the latest research progress in infrared in-memory sensing and computing devices. It first introduces the working principles and performance metrics of in-memory sensing and computing devices, then discusses in detail transistors and memristor-type devices with infrared band response, and finally looks forward to the development prospects of the field. Through innovation in new semiconductor materials and structures, the development trajectory of infrared in-memory sensing and computing devices has been significantly expanded, providing new impetus for the development of a new generation of information technology.

Flexible upconversion (UC) devices, owing to their unique combination of high–efficiency optical energy conversion and mechanical flexibility, have attracted increasing attention in the fields of optoelectronics, wearable devices, flexible displays, and biomedical applications. However, significant challenges remain in balancing optical performance, mechanical adaptability, long–term stability, and scalable fabrication, which limit their practical deployment. This review systematically introduces five representative upconversion mechanisms—excited–state absorption (ESA), energy transfer upconversion (ETU), energy migration upconversion (EMU), triplet–triplet annihilation upconversion (TTA–UC), and photon avalanche (PA)—highlighting their energy conversion principles, performance characteristics, and applicable scenarios. The article further delves into the flexible transition of upconversion devices, detailing not only the evolution of the luminescent layer from bulk crystals and nanoparticles to polymer composites and hybrid systems, but also the optimization of electrodes from rigid metal films to metal grids, carbon–based materials, and stretchable polymers. These developments significantly enhance the stability and reliability of flexible upconversion devices under bending, stretching, and complex mechanical deformation. Finally, emerging research directions are outlined, including multi–mechanism synergistic design, precise nanostructure engineering, interface optimization, and the construction of high–performance composite systems, emphasizing the broad potential of flexible UC devices in flexible displays, wearable health monitoring, solar energy harvesting, flexible optical communications, and biomedical photonic applications. This work provides critical insights for the design and application of high–performance flexible optoelectronic devices.