Multilayer perceptron Algorithm-Enabled flexible Laser-Induced graphene microwave sensor for intelligent biomechanical monitoring of sedentary behaviors

Sedentary behavior in contemporary office environments represents a critical health challenge, characterized by substantial risks of musculoskeletal fatigue and long-term physiological disorders, thereby necessitating innovative real-time motion monitoring solutions. This pioneering research presents a flexible microwave sensor based on laser-induced graphene (LIG) and a hybrid conductive pattern that integrates spiral inductors and interdigital capacitance within a coplanar waveguide (CPW) configuration. The sensor operated at a resonant frequency of 3.80 GHz, exhibiting exceptional performance with high sensitivity (3.45 MHz/°), robust stability, and the ability to distinguish bidirectional bending up to 90°. Furthermore, it demonstrated superior capability in tracking human joint movements in real time. By incorporating a multilayer perceptron (MLP) algorithm, the monitoring system achieved 97.35 % accuracy in recognizing nine distinct sitting postures. The research of MLP-assisted flexible LIG microwave sensor not only addresses critical challenges in sedentary behavior monitoring but also establishes a compelling paradigm for next-generation intelligent sensing technologies that bridge biomechanical understanding with advanced microwave electronic engineering.