Category: Automation and High-Throughput Technologies
A four-channel impedance analyzer module has been demonstrated for electro-impedance spectroscopy (EIS) for gold-based flexible chemi-impedance sensors for wearable applications. The module can perform time division multiplexed (TDM) impedance measurements on four sensors at 1 kHz. The system is characterized by ultra-low-volume (1-3 µL) testing of cortisol in perspired human sweat, continuous dose effects and temperature variations. In this work, detection of cortisol is shown for concentrations of 1pg/mL to 200ng/mL in synthetic and human sweat and translated as a change in impedance. Moreover, continuous dose test is performed to demonstrate the stability of sensor for elongated operation for cortisol concentration of 10 ng/mL to 200 ng/mL within clinical limits. Furthermore, temperature effect testing on the impedance of the sensor is performed using a temperature chamber for the clinical range of human temperature from 25° C to 40° C to show the stability of operation with 7.58% variability.
Devangsingh Sankhala– PhD student, The University of Texas at Dallas, Richardson, TX
The University of Texas at Dallas
Devangsingh G. Sankhala is currently pursuing his Ph.D. under the supervision of Dr. Shalini Prasad as a graduate research assistant at the Biomedical Microdevices and Nanotechnology Lab at the University of Texas at Dallas. He received his Master’s in Electrical Engineering in 2013 at the University of Texas at Dallas. His research interests include mixed-signal integrated circuit design and system level circuit design. His current research efforts focus on low power wearable bioelectronics to build diagnostic devices for biomolecules found in human sweat.