Fabrication of AlN-Based Flexible Piezoelectric Pressure Sensor to Integrate into an Artificial Pancreas

Present work reports the fabrication and characterization of a flexible AlN-based piezoelectric pressure sensor integrated, as insulin capsule punching detector, into an implantable artificial pancreas (AP), developed as automated treatment device for Type 1 diabetes. Ti/AlN/Ti trilayer was sputtered on a thin kapton substrate at room temperature, making the final device flexible and sensitive to the forces range of interest (0-4 N). The proposed preliminary prototype of AP comprises a refilling module, interfaced with the intestine wall, able to dock an ingestible insulin capsule. A linearly actuated needle punches the capsule to transfer the insulin to an implanted reservoir. The pressure sensor is located at the connection of the needle with the linear actuator to sense the occurred capsule punching. The sensor waveform output was processed to clearly identify the capsule punching.