# Portable Measurement System for the Characterization of Capacitive Field-Effect Sensors

## TL;DR

A portable, low-cost system was developed to measure and characterize capacitive sensors for on-site use, showing results comparable to expensive lab equipment.

## Contribution

A portable and user-friendly readout system for EISCAP sensors was developed and validated for on-site or point-of-care applications.

## Key findings

- The portable system produced EISCAP signals nearly identical to those from a commercial stationary analyzer.
- The system successfully measured pH and detected penicillin using EISCAP sensors.
- The system supports multiple characterization methods like impedance spectra and capacitance-voltage measurements.

## Abstract

A user-friendly, portable, low-cost readout system for the on-site or point-of-care characterization of chemo- and biosensors based on an electrolyte–insulator–semiconductor capacitor (EISCAP) has been developed using a thumb-drive-sized commercial impedance analyzer. The system is controlled by a custom Python script and allows to characterize EISCAP sensors with different methods (impedance spectra, capacitance-voltage, and constant-capacitance modes), which are selected in a user interface. The performance of the portable readout system was evaluated by pH measurements and the detection of the antibiotic penicillin, hereby using EISCAPs consisting of Al/p-Si/SiO2/Ta2O5 structures and compared to the results obtained with a stationary commercial impedance analyzer. Both the portable and the commercial systems provide very similar results with almost perfectly overlapping recorded EISCAP signals. The new portable system can accelerate the transition of EISCAP sensors from research laboratories to commercial end-user devices.