Bioelectronic Considerations in Biomedical Microneedles.

Microneedles (MNs), fabricated from diverse materials and assembled into arrays, have emerged as promising platforms for transdermal drug delivery and health monitoring. However, conventional MN-based theranostic systems mainly rely on passive diffusion and often involve complicated operational procedures, limiting delivery efficiency and real-time responsiveness. To overcome these limitations, MNs have been integrated with enhancement strategies such as magnetic fields, acoustics, and electronics to achieve active and programmable biomedical functions. Among these approaches, bioelectronics offer unique advantages in flexibility, conductivity, signal processing, and closed-loop control, thereby expanding the capabilities of MN systems in drug delivery and biosensing. Despite rapid progress, current studies mainly focus on material development and device fabrication, while the underlying design logic of bioelectronic MN systems remains insufficiently discussed. Herein, this review summarizes the recent advances in MN-assisted bioelectronic systems and proposes a bioelectronic design framework based on "front-end," "mid-end," and "back-end" functionalities. This framework provides a systematic understanding of how biointerfaces, signal transduction, and electronic modules cooperatively govern system performance. By highlighting the integration mechanisms and architectural strategies of bioelectronic MNs, this review offers insights into the rational design of next-generation wearable and closed-loop biomedical platforms.