A Biomimetic Palpation Platform for the Quantitative and Non-Invasive Assessment of Tissue Compliance

Physiological palpation serves as a primary clinical modality for identifying pathological changes in tissue compliance. However, its diagnostic precision is inherently limited by the subjective nature of human haptic perception and the lack of quantifiable mechanical metrics. This work describes a bio-inspired, portable tactile interface engineered for the non-invasive and real-time characterization of tissue stiffness. The system incorporates multimodal piezoresistive sensing elements that emulate the specific mechanotransduction functions of cutaneous receptors, namely Merkel disks and Ruffini endings. By integrating Hertzian contact mechanics to decouple pressure and strain signals, the platform analytically derives the effective Young's modulus of heterogeneous soft tissues. The developed sensor architecture exhibits a functional range of 0-600 kPa and a gauge factor of 10.8, facilitating high-fidelity detection of subcutaneous anomalies. Validation against various nodule geometries and depths demonstrates that the system achieves a diagnostic resolution surpassing conventional manual assessments. Furthermore, the integration of wireless data processing enables instantaneous, on-site mechanical profiling. This platform provides a scalable framework for objective diagnostics, robotic haptics, and continuous physiological monitoring, establishing a robust bridge between qualitative clinical observation and quantitative biomechanical analysis.