Design of scalable orthogonal digital encoding architecture for large-area flexible tactile sensing in robotics

Abstract: Human-like embodied tactile perception is crucial for the next-generation intelligent robotics. Achieving large-area, full-body soft coverage with high sensitivity and rapid response, akin to human skin, remains a formidable challenge due to critical bottlenecks in encoding efficiency and wiring complexity in existing flexible tactile sensors, thus significantly hinder the scalability and real-time performance required for human skin-level tactile perception. Herein, we present a new architecture employing code division multiple access-inspired orthogonal digital encoding to overcome these challenges. Our decentralized encoding strategy transforms conventional serial signal transmission by enabling parallel superposition of energy-orthogonal base codes from distributed sensing nodes, drastically reducing wiring requirements and increasing data throughput. We implemented and validated this strategy with off-the-shelf 16-node sensing array to reconstruct the pressure distribution, achieving a temporal resolution of 12.8 ms using only a single transmission wire. Crucially, the architecture can maintain sub-20ms latency across orders-of-magnitude variations in node number (to thousands of nodes). By fundamentally redefining signal encoding paradigms in soft electronics, this work opens new frontiers in developing scalable embodied intelligent systems with human-like sensory capabilities.