🤖 AI Summary
This work addresses the challenge of accurately mapping fully analog recurrent neural networks onto physical hardware by proposing the first scalable, fully analog Resonant Recurrent Neural Network (R²NN) architecture. Built upon a metamaterial-inspired circuit design, R²NN leverages electromechanical analogies to directly encode network parameters as circuit elements. It integrates globally coupled resistors and locally resonant units—both jointly trainable—to form frequency-selective current pathways that extract discriminative spectral features. Operating entirely in the analog domain without analog-to-digital conversion, R²NN enables real-time processing of raw time-series signals. Its cross-domain versatility is demonstrated across tactile sensing, speech recognition, and condition monitoring tasks, substantially overcoming the energy efficiency and latency limitations inherent in conventional digital systems for edge intelligence.
📝 Abstract
Physical neural networks offer a transformative route to edge intelligence, providing superior inference speed and energy efficiency compared to conventional digital architectures. However, realizing scalable, end-to-end, fully analog recurrent neural networks for temporal information processing remains challenging due to the difficulty of faithfully mapping trained network models onto physical hardware. Here we present a fully analog resonant recurrent neural network (R$^2$NN) implemented via a metacircuit architecture composed of coupled electrical local resonators. A reformulated mechanical-electrical analogy establishes a direct mapping between the R$^2$NN model and metacircuit elements, enabling accurate physical implementation of trained neural network parameters. By integrating jointly trainable global resistive coupling and local resonances, which generate effective frequency-dependent negative resistances, the architecture shapes an impedance landscape that steers currents along frequency-selective pathways. This mechanism enables direct extraction of discriminative spectral features, facilitating real-time temporal classification of raw analog inputs while bypassing analog-to-digital conversion. We demonstrate the cross-domain versatility of this framework using integrated hardware for tactile perception, speech recognition, and condition monitoring. This work establishes a scalable, fully analog paradigm for intelligent temporal processing and paves the way for low-latency, resource-efficient physical neural hardware for edge intelligence.