skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Potentiometric Sensor System with Self-Calibration for Long-Term, In Situ Measurements
We built an integrated solid-contact ion-selective electrode (SCISE) system with the functionality of self-calibration. A multiplexed SCISE sensor (K+ and NO3− vs. Ag/AgCl) was fabricated on printed-circuit board (PCB) substrates and was subsequently embedded into a microfluidic flow cell for self-calibration and flow-through analysis. A PCB circuit that includes modules for both sensor readout and fluid control was developed. The sensors showed a fast and near-Nernstian response (56.6 for the K+ electrode and −57.4 mV/dec for the NO3− electrode) and maintained their performance for at least three weeks. The sensors also showed a highly reproducible response in an automated two-point calibration, demonstrating the potential for in situ monitoring. Lastly, the sensor system was successfully applied to measure mineral nutrients in plant sap samples.  more » « less
Award ID(s):
1841473
PAR ID:
10395171
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Chemosensors
Volume:
11
Issue:
1
ISSN:
2227-9040
Page Range / eLocation ID:
48
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; (, 24th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2020))
    null (Ed.)
    We fabricated and evaluated multiplexed ion-selective electrodes (ISEs) by modifying printed circuit board (PCB). The multiplexed sensor consisted of all-solid-state K+ and NO3- ISEs, together with a Ag/AgCl reference. The sensor was further embedded in a microfluidic microchannel for in-line continuous analysis, and was characterized for up to one week of operation. Both ISEs showed a near-Nernstian response (~52 mV/dec) and reasonable stabilities (baseline drift ~2.9 mV/day). The sensor provides a versatile and low-cost tool for monitoring concentrations of different ions in many biomedical, environmental and agricultural applications. 
    more » « less
  2. ; (, Electroanalysis)
    Abstract Multiplexed solid‐contact ion‐selective electrodes (SCISEs) are fabricated using printed circuit board (PCB) and mesoporous carbon black (MCB) as ion‐to‐electron transducer (solid contact). Four sensor configurations were examined and showed that in addition to MCB, the sensor configuration plays crucial role in the stability of the potential response. The enhanced sensor stability was also linked with suppression of transmembrane flux of water. The sensors exhibited near‐Nernstian sensitivity (58.1 mV/dec for K+ISEs and −55.1 mV/dec for NO3‐ISEs), low detection limits (1.5–2.2 μM), and good short‐term stability (∼0.1 mV/min). Sensors can be stored dry and used without preconditioning. This work demonstrates a promising approach to combining PCB technology and carbon black for large‐scale production of low cost ISEs for point‐of‐care testing, wearables, orin situfield measurements. 
    more » « less
  3. ; ; (, Proceedings of the 26th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2022))
    We developed a potentiometric sensor system that includes a portable device and a multiplexed sensor based on solid-contact ion-selective electrodes (SCISE). SCISEs are fabricated using printed circuit board (PCB) and mesoporous carbon black (MCB) as the ion-to-electron transducer. The device supports sensor readout as well as automated sensor calibration, making it suitable for long term, in situ measurements. 
    more » « less
  4. (, Smart materials and structures)
    In this paper, we report the development of tailored 3D-structured (engineered) polymer-metal interfaces to create enhanced ‘engineered ionic polymer metal composite’ (eIPMC) sensors towards soft, self-powered, high sensitivity strain sensor applications. We introduce a novel advanced additive manufacturing approach to tailor the morphology of the polymer-electrode interfaces via inkjet-printed polymer microscale features. We hypothesize that these features can promote inhomogeneous strain within the material upon the application of external pressure, responsible for improved compression sensing performance. We formalize a minimal physics-based chemoelectromechanical model to predict the linear sensor behavior of eIPMCs in both open-circuit and short-circuit sensing conditions. The model accounts for polymer-electrode interfacial topography to define the inhomogeneous mechanical response driving electrochemical transport in the eIPMC. Electrochemical experiments demonstrate improved electrochemical properties of the inkjet-printed eIPMCs as compared to the standard IPMC sensors fabricated from Nafion polymer sheets. Similarly, compression sensing results show a significant increase in sensing performance of inkjet-printed eIPMC. We also introduce two alternative methods of eIPMC fabrication for sub-millimeter features, namely filament-based fused-deposition manufacturing and stencil printing, and experimentally demonstrate their improved sensing performance. Our results demonstrate increasing voltage output associated to increasing applied mechanical pressure and enhanced performance of the proposed eIPMC sensors against traditional IPMC based compression sensors. 
    more » « less
  5. (, Smart materials and structures)
    In this paper, we report the development of tailored 3D-structured (engineered) polymer-metal interfaces to create enhanced 'engineered ionic polymer metal composite' (eIPMC) sensors towards soft, self-powered, high sensitivity strain sensor applications. We introduce a novel advanced additive manufacturing approach to tailor the morphology of the polymer-electrode interfaces via inkjet-printed polymer microscale features. We hypothesize that these features can promote inhomogeneous strain within the material upon the application of external pressure, responsible for improved compression sensing performance. We formalize a minimal physics-based chemoelectromechanical model to predict the linear sensor behavior of eIPMCs in both open-circuit and short-circuit sensing conditions. The model accounts for polymer-electrode interfacial topography to define the inhomogeneous mechanical response driving electrochemical transport in the eIPMC. Electrochemical experiments demonstrate improved electrochemical properties of the inkjet-printed eIPMCs as compared to the standard IPMC sensors fabricated from Nafion polymer sheets. Similarly, compression sensing results show a significant increase in sensing performance of inkjet-printed eIPMC. We also introduce two alternative methods of eIPMC fabrication for sub-millimeter features, namely filament-based fused-deposition manufacturing and stencil printing, and experimentally demonstrate their improved sensing performance. Our results demonstrate increasing voltage output associated to increasing applied mechanical pressure and enhanced performance of the proposed eIPMC sensors against traditional IPMC based compression sensors. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email