Chemical and pH sensors based on the swelling behavior of hydrogels

Gerlach, Gerald; Guenther, Margarita; Sorber, Joerg; Suchaneck, G.; Arndt, Karl‐Friedrich; Richter, Andreas

doi:10.1016/j.snb.2005.03.040

Cited by 220 publications

(141 citation statements)

References 16 publications

Supporting

Mentioning

134

Contrasting

Order By: Relevance

“…Gel-coated silicon microcantilevers can be used to detect swelling in response to changes in pH or other species [69,189,190]. Changes in swelling can also be sensed by attaching the gel to a pressure sensor.…”

Section: Gel Sensorsmentioning

confidence: 99%

Polymer Gel Actuators: Fundamentals

Calvert

2009

Biomedical Applications of Electroactive Polymer Actuators

View full text Add to dashboard Cite

One view of materials development is to search for what materials correspond to empty spaces on a hypothetical multi-dimensional map of the properties of available materials. Following a biomimetic philosophy, for instance, it can be seen that tough ceramics and moldable short fiber composites with high moduli are possible but absent from the list of available synthetic materials. Likewise artificial muscle is missing, where the properties are defined as a developed stress of over 300 kPa, a linear contraction of 25 % and a response time of below one second. Currently dielectric elastomers come closest but have disadvantages [1,2].The actin-myosin muscle system provides the performance target for electroactive polymer actuators [3,4]. The process is driven chemically by the energy change from hydrolysis of the polyphosphate bond as ATP (adenosine triphosphate) binds to myosin and is converted to ADP (adenosine diphosphate) and phosphate. A simple chemical analogy suggests that muscle-like gels should be feasible but it is now clear that the task is much harder than it seems.Early work on gel actuation by Katchalsky-Katzir demonstrated that engines could be built using the chemical energy in diluting a lithium bromide solution to drive contraction and expansion of a collagen belt [5]. In essence, the collagen expands to take up the salt solution or contract to exclude the water. This change is both a molecular conformation change and a volume change. Other chemically driven gels, for instance polyacrylic acid fibers [6] which respond to a pH change, also rely on a solubility change giving rise to a volume change.

show abstract

Section: Gel Sensorsmentioning

confidence: 99%

Polymer Gel Actuators: Fundamentals

Calvert

2009

Biomedical Applications of Electroactive Polymer Actuators

View full text Add to dashboard Cite

show abstract

“…In technical applications, hydrogels serve as basic building blocks for gel electrophoresis or size exclusion chromatography, etc. Moreover they are nowadays implementet as "intelligent" chemo-mechanical materials using them as stimuli-responsive sensor-actor systems [1] based on their high sensitivity to environmental conditions [2] such as pH [3,4], temperature [5], solvent composition [3], light or pressure [2]. In biological contexts, hydrogels have become ideal model systems for tissue matrices due to their similarity to the extra-cellular matrix (ECM).…”

Section: Introductionmentioning

confidence: 99%

Diffusion and interaction in PEG-DA hydrogels

2013

View full text Add to dashboard Cite

Polyethylenglycol (PEG) hydrogels are widely used as tuneable substrates for biological and technical applications due to their good biocompatibility and their high hydrophilicity. Here we compare the mesh size and diffusion characteristics of PEG hydrogels by analyzing the diffusion of solutes with different, well-defined sizes over long and short time scales. Interestingly, one can tune the mesh size and the density of the gel simply by changing the inital concentrations of the PEG-diacrylate (PEG-DA) polymer, which also enhances the solute uptake in equilibrium through the interaction with the PEG chains. This increased uptake can be characterized by an enhancement factor determined by partition ratio analysis. It increases linearly with the polymer volume fraction, but is not caused by immobilization inside the hydrogel as evident from FRAP measurements, thus rendering these hydrogels ideal materials for i.e. drug delivery applications

show abstract

“…This simplification is necessary, because more sophisticated modelling approaches for hydrogels, like e.g. Burger's model (Gerlach et al, 2005), contain too many free parameters for a unique solution of the equation system. The application of Mason's transmission line model (Bruenig, 2011;Mason, 1950) yields for the described load case with G * = G + iωη for the hydrogel and the index w denoting the properties of the surrounding liquid half space.…”

Section: Indirect Measurementsmentioning

confidence: 99%

Paradigm change in hydrogel sensor manufacturing: from recipe-driven to specification-driven process optimization

Windisch¹,

Eichhorn²,

Lienig³

et al. 2016

J. Sens. Sens. Syst.

View full text Add to dashboard Cite

Abstract. The volume production of industrial hydrogel sensors lacks a quality-assuring manufacturing technique for thin polymer films with reproducible properties. Overcoming this problem requires a paradigm change from the current recipe-driven manufacturing process to a specification-driven one. This requires techniques to measure quality-determining hydrogel film properties as well as tools and methods for the control and optimization of the manufacturing process. In this paper we present an approach that comprehensively addresses these issues. The influence of process parameters on the hydrogel film properties and the resulting sensor characteristics have been assessed by means of batch manufacturing tests and the application of several measurement techniques. Based on these investigations, we present novel methods and a tool for the optimization of the cross-linking process step, with the latter being crucial for the sensor sensitivity. Our approach is applicable to various sensor designs with different hydrogels. It has been successfully tested with a sensor solution for surface technology based on PVA/PAA hydrogel as sensing layer and a piezoelectric thickness shear resonator as transducer. Finally, unresolved issues regarding the measurement of hydrogel film parameters are outlined for future research.

show abstract

Chemical and pH sensors based on the swelling behavior of hydrogels

Cited by 220 publications

References 16 publications

Polymer Gel Actuators: Fundamentals

Polymer Gel Actuators: Fundamentals

Diffusion and interaction in PEG-DA hydrogels

Paradigm change in hydrogel sensor manufacturing: from recipe-driven to specification-driven process optimization

Contact Info

Product

Resources

About