In this work, synthesis and swelling behavior of a superabsorbent hydrogel based on Pectin (Pc) and polyacrylonitrile (PAN) were investigated. A mechanism for hydrogel formation was proposed and the structure of the product was established using FTIR spectroscopy. The Pc-poly (sodium acrylate-co-acrylamide) hydrogel exhibited a pH-responsive swelling-deswelling behavior at pH’s 2 and 8. This on...

This paper reports development of a novel, flexible hydrogel based capacitive pressure sensor. It features a simple design of hydrogel thin film sandwiched between two gold electrodes. The sensor shows linear increase in output with increase in pressure. The microporous network of hydrogel enables high water retention while its flexible and stretchable structure ensures usage over large areas. ...

Phase mask interference lithography was employed to fabricate three-dimensional (3D) hydrogel structures with high surface area on neural prosthetic devices. A random terpolymer of poly(hydroxyethyl methacrylate- ran-methyl methacrylate- ran-methacrylic acid) was synthesized and used as a negative-tone photoresist to generate bicontinuous 3D hydrogel structures at the submicrometer scale. We de...

We propose a unique process to generate non-spherical hydrogel microstructures using an aqueous two-phase system (ATPS) in a non-equilibrium state. A dextran (Dex) solution containing cells and hydrogel precursor (sodium alginate; NaA) was introduced into microfabricated chambers, which was gradually shrunk and deformed after pouring a polyethylene glycol (PEG) solution. Following the addition ...

Hydrogel is a useful material for biomedical applications because of its softness and solute permeability, but the use of hydrogel as a structural material for microfluidic devices is challenging due to the lack of a hydrogel-solid bonding method. We have developed a hydrogel reactive microbonding (HRMB) method that enables the use of Tetra-PEG gel, which has an extraordinarily uniform network ...

Due to their hydrophilic, biocompatible, and highly tunable nature, hydrogel materials have attracted strong interest in the recent years for numerous biotechnological applications. In particular, their solution-like environment and non-fouling nature in complex biological samples render hydrogels as ideal substrates for biosensing applications. Hydrogel coatings, and later, gel dot surface mic...

A pH-responsive hydrogel system was prepared by free radical polymerization of acrylamide and methyl acrylic acid in the presence of N-N′-methylene bisacrylamide. Sodium bicarbonate was further applied as a blowing agent, which afforded a porous hydrogel structure. The hydrogel system achieved a constant super swelling rate within simulated intestinal buffer (~4%/min) and remained relatively st...

The use of hydrogel nanostructured patterns and films in biomedical micro- and nanodevices requires the ability to analyze and understand their response properties at the nanoscale. Herein, the thermoresponse behavior of atom transfer radical polymerization (ATRP) grown poly(ethylene glycol) n dimethacrylate (PEGnDMA) cross-linked poly(N-isopropyl acrylamide) (PNIPAAm) hydrogel thin films over ...

This paper describes a novel platform that utilizes micropatterning and electrochemistry to release cells-on-hydrogel microstructures from conductive indium tin oxide (ITO) substrates. In this approach, UV photopolymerization was employed to micropattern heparin-based hydrogels onto glass substrates containing ITO electrodes. ITO/glass substrates were first functionalized with acrylated silane ...

The structural evolution of Bragg diffracting inverse opal hydrogel sensors during swelling is directly observed by two-photon laser scanning fluorescence microscopy and compared to predictions from finite element analysis. A fluorescently labeled pH-sensitive hydrogel is UV-polymerized in a dried polystyrene colloidal crystal template, which is etched to yield an inverse opal. Fluorescence ima...