A cylindrical projection lithography-fabricated flexible on-catheter in situ integrated sensor for continuous in-artery blood pressure monitoring.

Continuous and accurate blood pressure monitoring is vital for the diagnosis and management of life-threatening cardiovascular diseases. Conventional fluid-filled catheter systems are fundamentally constrained by distortion, infection risks, and limited portability. In parallel, Micro-Electro-Mechanical System (MEMS) sensors assembled to catheters face miniaturization bottlenecks and packaging complexity. Here, we present a flexible on-catheter interventional pressure sensor (CIPS), leveraging suspended-graphene arrays for pressure sensing and dual polymer encapsulation layers for hermetic and waterproof encapsulation. The highly integrated CIPS with compact architecture is enabled by cylindrical projection lithography (CPL)-based 3D in situ MEMS fabrication process. By introducing interdigital electrodes (IDEs) in sensitive areas and optimizing structural parameters, CIPS delivers an ultrafast response (<0.36 s), exceptional sensitivity (3.5 × 10⁻⁶·mmHg⁻¹), and a broad detection range (6-380 mmHg), outperforming state-of-the-art suspended-graphene pressure sensors. The dual-layer polymer encapsulation strategy ensures the hermetic and waterproof integrity of CIPS. Crucially, CIPS enables real-time monitoring of arterial pressure in the rat abdominal aorta, marking the first demonstration of suspended graphene in animal-level bioelectronic sensing. This work has also underscored the translational potential for CPL-based 3D in situ MEMS fabrication strategy.