Funktionsprinzip und Anwendung der Kraftkompensationsmessmethode für miniaturisierte hydrogelbasierte Sensoren

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

Abstract

Chemical sensors that use a stimulus-responsive hydrogel as a transducer offer many advantages. The hydrogels are inexpensive, easy to manufacture and can be designed for a wide variety of measured variables. Sensor setups that convert the stimulus-dependent swelling pressure into an electrical measurement signal can be easily miniaturized and used as a platform for different types of hydrogels. However, the main disadvantages of hydrogel-based sensor principles are creep and long settling times in the minutes to hours range due to tedious diffusion processes and viscoelastic behavior of hydrogels. Force compensation is a measurement method to successfully counteract these two effects by suppressing the time-driving volume phase transition of the hydrogel. However, the actuator required for this prevented miniaturization of sensor setups in previous works. In this work, therefore, a different type of force compensation is shown which allows the many advantages of the force compensation method to be applied to a hydrogel sensor while ensuring small dimensions of the sensor assembly. This is accomplished by incorporating the swell-suppressing actuator directly into the hydrogel transducer. In this way, the swelling pressure compensation occurs in the hydrogel itself. For this purpose, the hydrogel is designed as a bisensitive hydrogel. As a result, the sensor setup is significantly miniaturized and simplified due to the elimination of complex actuator setups. At the same time, a high settling time reduction is achieved compared to the conventional uncompensated measuring method and the previous compensation approaches are surpassed with a minimum settling time of approx. 3 min. Furthermore, a significant reduction of undesired hysteresis characteristics and the possibility to extend the measuring range is shown. The measurement method is demonstrated using the example of a piezoresistive hydrogel sensor and is transferable to other hydrogel-based sensor principles to improve the sensor properties.

Details

OriginalspracheDeutsch
Seiten (von - bis)465-477
Seitenumfang13
FachzeitschriftTechnisches Messen
Jahrgang89
Ausgabenummer7-8
PublikationsstatusVeröffentlicht - 1 Juli 2022
Peer-Review-StatusJa

Externe IDs

ORCID /0000-0002-7062-9598/work/174430580

Schlagworte

Schlagwörter

  • Chemical sensors, force compensation, force rebalance, hydrogel-based sensors, settling time, smart hydrogels