Advanced Characterization of Liquid-Gated Extended-Gate FET Sensors

Liquid-gated extended-gate Field-Effect Transistors (EGFETs) leverage the robustness and scalability of commercial CMOS technology while enabling direct interaction with (bio)chemical environments using an exposed electrode which is connected to the FET's gate. By post-processing commercial CMOS wafers we fabricated EGFET chips with varying EGFET dimensions. This internship focuses on the advanced electrical and electrochemical characterization of these liquid‑gated EGFET sensors, aiming to evaluate their potential as fully integrated pH and ion sensing platforms. During this project the student will electrically characterize standard liquid‑gated FET operation, sensor stability and sensitivity across varying electrolyte conditions pH and ionic strength. The electrical measurements will be executed on a probe station while a microfluidic setup enables the automated exchange between different electrolyte conditions. Crucial for the EGFET's pH and ion sensing performance is the type and quality of the exposed electrode surface. Therefore, the influence of electrode surface functionalization on EGFET performance will be explored. Benchmarks include Nernstian response, drift, hysteresis, and noise characteristics. The results will contribute to the development of a next‑generation fully-integrated ion and pH sensing platform.