Smart Hydrogel Swelling State Detection Based on a Power-Transfer Transduction Principle

authored by: Benozir Ahmed, Christopher F. Reiche, Jules J. Magda, Florian Solzbacher, Julia Körner
Abstract: Stimulus-responsive (smart) hydrogels are a promising sensing material for biomedical contexts due to their reversible swelling change in response to target analytes. The design of application-specific sensors that utilize this behavior requires the development of suitable transduction concepts. The presented study investigates a power-transfer-based readout approach that is sensitive to small volumetric changes of the smart hydrogel. The concept employs two thin film polyimide substrates with embedded conductive strip lines, which are shielded from each other except at the tip region, where the smart hydrogel is sandwiched in between. The hydrogel’s volume change in response to a target analyte alters the distance and orientation of the thin films, affecting the amount of transferred power between the two transducer parts and, consequently, the measured sensor output voltage. With proper calibration, the output signal can be used to determine the swelling change of the hydrogel and, consequently, to quantify the stimulus. In proof-of-principle experiments with glucose- and pH-sensitive smart hydrogels, high sensitivity to small analyte concentration changes was found along with very good reproducibility and stability. The concept was tested with two exemplary hydrogels, but the transduction principle in general is independent of the specific hydrogel material, as long as it exhibits a stimulus-dependent volume change. The application vision of the presented research is to integrate in situ blood analyte monitoring capabilities into standard (micro)catheters. The developed sensor is designed to fit into a catheter without obstructing its normal use and, therefore, offers great potential for providing a universally applicable transducer platform for smart catheter-based sensing.
Organisation(s): Faculty of Electrical Engineering and Computer Science
External Organisation(s): University of Utah
Type: Article
Journal: ACS Applied Polymer Materials
Volume: 6
Pages: 5544-5554
No. of pages: 11
Publication date: 10.05.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Process Chemistry and Technology, Polymers and Plastics, Organic Chemistry
Electronic version(s): https://doi.org/10.1021/acsapm.4c00808 (Access: Open)

BibTeX

@article{56accb98b7c947b39b173cad71a21625,
title = "Smart Hydrogel Swelling State Detection Based on a Power-Transfer Transduction Principle",
abstract = "Stimulus-responsive (smart) hydrogels are a promising sensing material for biomedical contexts due to their reversible swelling change in response to target analytes. The design of application-specific sensors that utilize this behavior requires the development of suitable transduction concepts. The presented study investigates a power-transfer-based readout approach that is sensitive to small volumetric changes of the smart hydrogel. The concept employs two thin film polyimide substrates with embedded conductive strip lines, which are shielded from each other except at the tip region, where the smart hydrogel is sandwiched in between. The hydrogel{\textquoteright}s volume change in response to a target analyte alters the distance and orientation of the thin films, affecting the amount of transferred power between the two transducer parts and, consequently, the measured sensor output voltage. With proper calibration, the output signal can be used to determine the swelling change of the hydrogel and, consequently, to quantify the stimulus. In proof-of-principle experiments with glucose- and pH-sensitive smart hydrogels, high sensitivity to small analyte concentration changes was found along with very good reproducibility and stability. The concept was tested with two exemplary hydrogels, but the transduction principle in general is independent of the specific hydrogel material, as long as it exhibits a stimulus-dependent volume change. The application vision of the presented research is to integrate in situ blood analyte monitoring capabilities into standard (micro)catheters. The developed sensor is designed to fit into a catheter without obstructing its normal use and, therefore, offers great potential for providing a universally applicable transducer platform for smart catheter-based sensing.",
keywords = "electromagnetic power transfer, flexible sensors, in situ analyte monitoring, inductive coupling, microcatheter, Stimulus-responsive hydrogel, swelling state transduction",
author = "Benozir Ahmed and Reiche, {Christopher F.} and Magda, {Jules J.} and Florian Solzbacher and Julia K{\"o}rner",
note = "Funding Information: The reported research was supported by the Joe W. and Dorothy Dorsett Brown Foundation, the Olive Tupper Foundation, and the National Institute of General Medical Sciences of the National Institutes of Health (NIH) under Award 1R41GM130241 awarded to Sentiomed, Inc. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or the foundations. ",
year = "2024",
month = may,
day = "10",
doi = "10.1021/acsapm.4c00808",
language = "English",
volume = "6",
pages = "5544--5554",
journal = "ACS Applied Polymer Materials",
issn = "2637-6105",
publisher = "American Chemical Society",
number = "9",
}