Organic electrochemical transistors (OECTs) have attracted significant attention due to their unique ionic-electronic charge coupling, which holds promise for use in a variety of bioelectronics. However, the typical electronic components of OECTs, such as the rigid metal electrodes and aqueous electrolytes, have limited their application in solid-state bioelectronics that requires design flexibility and a variety of form factors. Here, the fabrication of a solid-state homojunction OECT consisting of a pristine polymer semiconductor channel, doped polymer semiconductor electrodes, and a solid electrolyte is demonstrated. This structure combines the photo-crosslinking of all of the electronic OECT components with the selective doping of the polymer semiconductor. Three Lewis acids (gold (III) chloride (AuCl 3 ), iron (III) chloride (FeCl 3 ), and copper (II) chloride (CuCl 2 ) ) are utilized as dopants for the metallization of the polymer semiconductor. The AuCl 3 -doped polymer semiconductor with an electrical conductivity of ≈100 S cm −1 is successfully employed as the source, drain, and gate electrodes for the OECT, which exhibited a high carrier mobility of 3.4 cm 2 V −1 s −1 and excellent mechanical stability, with negligible degradation in device performance after 5000 cycles of folding at a radius of 0.1 mm. Homojunction OECTs are then successfully assembled to produce NOT, NAND, and NOR logic gates.

Despite their high optical transparency and electrical conductivity, the commercialization of silver nanowire materials as transparent electrodes is challenging owing to the lack of a scalable micropatterning process. This paper proposes a versatile method for photopatterning silver nanowire networks, based on photoinduced nanowire−nanowire and nanowire−substrate cross-linking. Because the proposed method requires only a small loading of the photocross-linking agent, the intrinsic physical characteristics of the silver nanowire network can be preserved. Furthermore, through the roughness-assisted wetting phenomenon, the resulting patterns can be selectively hybridized to form bilayered nanowire/conducting polymer electrodes. The resulting hybrid transparent electrodes exhibit a low roughness, excellent tolerance to oxidation or electrochemical processes, and mechanical stability against bending without compromising the excellent optical/electrical characteristics achievable from the pristine silver nanowire network. These benefits are integrated to assemble an active-matrix-driven electrochromic display. The proposed method can thus facilitate the practical application of silver nanowire network based transparent electrodes.

Extracting valuable information from the overflowing data is a critical yet challenging task. Dealing with high volumes of biometric data, which are often unstructured, nonstatic, and ambiguous, requires extensive computer resources and data specialists. Emerging neuromorphic computing technologies that mimic the data processing properties of biological neural networks offer a promising solution for handling overflowing data. Here, the development of an electrolyte-gated organic transistor featuring a selective transition from short-term to long-term plasticity of the biological synapse is presented. The memory behaviors of the synaptic device were precisely modulated by restricting ion penetration through an organic channel via photochemical reactions of the cross-linking molecules. Furthermore, the applicability of the memory-controlled synaptic device was verified by constructing a reconfigurable synaptic logic gate for implementing a medical algorithm without further weight-update process. Last, the presented neuromorphic device demonstrated feasibility to handle biometric information with various update periods and perform health care tasks.