Hydrogel for Photonics
Light guidance and manipulation in photonics have permeated numerous fields, including common communication practices and complex applications in the areas of robotics and nanomedical research. The potential of hydrogels to seamlessly integrate photonics and bioengineering arises from their ability to guide light and their compatibility with live tissue in optical, chemical, physiological, and mechanical domains.
Introduction to Photonics
Photonics can be succinctly described as the manipulation and control of light, regardless of its various characteristics, primarily through specific structures that interact with light. Naturally, achieving light guidance requires certain conditions like transparency because materials that are not transparent hinder the movement of photons rather than facilitating it. In most cases, when light waves interact with surface structures such as edges, they undergo diffraction or plasmonic resonances which subsequently lead to changes in properties like wavelength (colors within the visible spectrum).
Fig. 1 Overview of hydrogel optics. (Guimarães CF, et al., 2021)
Photonic Applications of Hydrogel
The essential characteristics for hydrogels to guide and manipulate light can be narrowed down to two parameters. The first parameter is the ability to transmit light efficiently, ensuring transparency of the material. The second parameter involves the structure, which allows either guiding light over significant distances within the material (such as through layers with different refractive indices) or interacting with light in a way that leads to measurable changes as a response to target analytes' presence.
- Thin Hydrogel Films
Hydrogel thin films primarily depend on variations in the swelling or deswelling of polymer meshes, leading to modifications in film thickness or height and subsequently influencing their interaction with light. Functionalized hydrogels possess the ability to selectively bind molecules and induce alterations in water content, rendering them suitable for utilization as sensing platforms. Moreover, optical thin films are frequently combined with other structures like nanoparticles to integrate the characteristics of hydrogel films with plasmonic-like sensing or even holographic arrangements. - Optical Hydrogel Fibers and Waveguides
Optical waveguides encompass a diverse range of structures that effectively guide light through space. Specifically, optical fibers exhibit superior efficiency in guiding light compared to other types of waveguides. Hydrogel optical fibers have demonstrated exceptional performance in efficiently guiding light over long distances and seamlessly integrating with living tissues, thereby offering significant advantages over solid-state fibers by enhancing biological compatibility. The utilization of hydrogel optical fibers has been extensively employed in the field of sensors. - Bioinspired Structured Hydrogels
The field of bioinspired structured photonic hydrogels encompasses the development of artificial materials that emulate natural systems to achieve distinctive optical properties. These materials integrate principles from photonics, hydrogels, and biological structures to enable specific functionalities. This application of hydrogel photonics facilitates rapid and label-free detection of cellular events through straightforward analysis of the material's interaction with light and subsequent alterations in color wavelength.
Fig. 2 Thin hydrogel films. (Guimarães CF, et al., 2021)
Fig. 3 Optical hydrogel fibers. (Guimarães CF, et al., 2021)
Fig. 4 Structured hydrogels. (Guimarães CF, et al., 2021)
The Hydrogel Development Services We Provide
Want to learn more about hydrogel for photonics? Matexcel provides high-quality hydrogel development services, and hydrogel analysis and characterization services. Please feel free to contact us for further information.
Reference
- Guimarães CF.; et al. Engineering Hydrogel-Based Biomedical Photonics: Design, Fabrication, and Applications. Adv Mater. 2021 Jun;33(23):e2006582.