Il‐Young Jo

The rapid growth of data‐intensive computing has exposed the physical limitations of conventional hardware architectures. While accumulative multistate memory devices offer low‐power alternatives, incorporating multistate reconfigurability into switching devices enables fully integrated, multifunctional neuromorphic operations across both logic and memory. Herein, we report programmable multistate logic circuits based on organic neuromorphic devices. By leveraging the intrinsic learning capability of organic electrochemical diodes (OECDs), multiple logic functions are realized within a single diode‐resistor configuration. The channel conductance of each OECD is dynamically modulated by the polarity and frequency of the input voltage, enabling seamless reconfiguration to execute custom logic operations (e.g., AND/OR and XOR/unknown). Furthermore, we demonstrate a functional half‐adder by cascading two multistate logic circuits as a proof‐of‐concept neuromorphic computing architecture. These results establish a promising pathway toward on‐chip, learning‐based digital circuitry with potential relevance to future neuromorphic computing applications.

This review addresses the environmental challenges arising from the proliferation of plastic and electronic waste (E‐waste), driven by global economic and demographic expansion. Since the 1950s, the mass production of plastics has seriously threatened global sustainability, lacking effective post‐use management. E‐waste worsens the issue due to low recyclability and high toxicity. Resolving this requires improving biodegradability. The paper explores eco‐friendly biodegradable materials for a zero‐e‐waste society, focusing on multifunctional plastics in electronics, providing a comprehensive guide to material selection, and illustrating novel concepts through recent trials. The goal is fully biodegradable electronics, but transitioning from conventional material systems is complex. Notably, rendering engineering plastics in electronics biodegradable surpasses simply substituting conventional plastics. Thus, it is delved into various research initiatives focused on biodegradable materials for electronics, highlighting a systematic approach toward creating a fully integrated, biodegradable electronic system. This includes exploring the mechanisms of biodegradation and the integration of printed circuit boards (PCBs), a critical component in electronics. Achieving this represents a challenging but promising step toward a sustainable electronic future.

For optimizing steady‐state performance in organic electrochemical transistors (OECTs), both molecular design and structural alignment approaches must work in tandem to minimize energetic and microstructural disorders in polymeric mixed ionic–electronic conductor films. Herein, a series of poly(diketopyrrolopyrrole)s bearing various lengths of aliphatic–glycol hybrid side chains (PDPP‐mEG; m = 2–5) is developed to achieve high‐performance p‐type OECTs. PDPP‐4EG polymer with the optimized length of side chains exhibits excellent crystallinity owing to enhanced lamellar and backbone interactions. Furthermore, the improved structural ordering in PDPP‐4EG films significantly decreases trap state density and energetic disorder. Consequently, PDPP‐4EG‐based OECT devices produce a mobility–volumetric capacitance product ([µC*]) of 702 F V⁻¹ cm⁻¹ s⁻¹ and a hole mobility of 6.49 ± 0.60 cm² V⁻¹ s⁻¹. Finally, for achieving the optimal structural ordering along the OECT channel direction, a floating film transfer method is employed to reinforce the unidirectional orientation of polymer chains, leading to a substantially increased figure‐of‐merit [µC*] to over 800 F V⁻¹ cm⁻¹ s⁻¹. The research demonstrates the importance of side chain engineering of polymeric mixed ionic–electronic conductors in conjunction with their anisotropic microstructural optimization to maximize OECT characteristics.