Pressure Sensing and Kinetic Modeling of Oxygen-Releasing Endoperoxides for Chemically Driven Micro-Actuation

This work presents a pressure-based sensing framework to directly track and monitor oxygen release from anthracene-endoperoxide (ANT-EPO) decomposition in an aqueous environment. ANT-EPO shows potential as an on-demand gas source for applications in pneumatic actuators and soft robotics. However, its integration into functional systems requires accurate, real-time characterization of oxygen release kinetics. To address this, a sealed measurement chamber coupled with a calibrated low-pressure sensor was employed to enable long-term, continuous tracking of oxygen release under ambient conditions (37 °C) and at room temperature. A multistep signal processing pipeline was implemented to extract meaningful kinetic information from the pressure response resulting from oxygen release. The raw pressure-time signals were processed using an adaptive Savitzky-Golay (SG) smoothing followed by discrete wavelet transform (DWT) to recover clean reaction kinetics that were further analyzed using kinetic modeling. The denoised pressure data revealed temperature-sensitive decomposition kinetics, with room temperature experiments exhibiting a sigmoidal profile, well captured by a logistic model (<i>R</i> ² = 0.993, RMSE = 0.17 kPa), outperforming a first-order model in capturing this multiphase behavior. In contrast, under constant 37 °C conditions, the pressure rise followed a first-order kinetic profile (<i>R</i> ² = 0.995), reflecting accelerated and linear oxygen release kinetics. These findings demonstrate that pressure sensing can serve as a standalone, real-time, and quantitative characterization of oxygen release kinetics, even for slow-reacting systems. This methodology establishes a structured sensing framework combined with a multistage processing pipeline for tracking gas release dynamics and capturing dynamic deviations from ideal kinetics. This study lays the groundwork for pressure-driven actuator designs and advanced feedback control in soft robotic systems, highlighting the broader impact of oxygen-releasing compounds.