Hydrogels patterning

Schmidt T, Monch JI, Arndt KF (2006) Temperature-sensitive hydrogel pattern by electron-beam lithography. Macromol Mater Eng 291(7) 755-761... 

Figure 19.2. Absorption spectra of hydrogels patterned with CdS nanoparticles. From [15].

Fig. 5 Hydrogel patterns produced (dry state) by UV photopolymerization (50 mW/cm ) (Paschew 2006). The right-hand picture is an enlarged image of the original one left side)...

Another way of UV patterning is the coating of a dry film of responsive polymer with a photoresist. Resist lithography and dry etching in oxygen plasma yield hydrogel patterns down to 2.5 pm, see Figure 14. ... 

The swelling pattern considered above allows us to understand the peculiarities of the behavior of SAH and the effects encountered during their application. The kinetic aspects of swelling seem to be as important as the thermodynamics of this process. Therefore, we shall touch upon some problems concerning the kinetics of hydrogel swelling and deswelling. 

The radial-distribution function curves of all samples are shown in Figs. 5 through 10. The RDF patterns of samples A, B, C and D are very similar to each other. Every hydrogel shows a sign of the Si(Al)-0 bond at the radius of 1.6-1.7A as a trace of a shoulder in Figs. 5 through 10. 

Matsumoto S, Yamaguchi S, Ueno S, Komatsu H, Ikeda M, Ishizuka K, Iko Y, Tabata KV, Aoki H, Ito S, Noji H, Hamachi I (2008) Photo gel-sol/sol-gel transition and its patterning of a supramolecular hydrogel as stimuli-responsive. Biomaterials 14 3977-3986... 

Direct protein patterning Laminin Polyacrylamide-based hydrogel... 

RGDS-PEG PEG-DA Human dermal fibroblasts Two-photon laser scanning photolithography to crosslink peptide-PEG inside a precrosslinked hydrogel to create 3D cell adhesion patterns 2008 [175]... 

Ahmed WW, Wolfram T, Goldyn AM et al (2010) Myoblast morphology and organization on biochemically micro-patterned hydrogel coatings under cyclic mechanical strain. Biomaterials 31 250-258... 

Takahashi H, Emoto K, Dubey M et al (2008) Imaging surface immobilization chemistry correlation with cell patterning on non-adhesive hydrogel thin films. Adv Funct Mater 18(14) 2079-2088... 

The latter can be defined as microchannels that allow fluid to flow under one set of conditions, but completely seals off flow under other conditions. This effect has been demonstrated in a number of ways for example, by patterning an array of hydrogels within a microchannel or by patterning two strips of responsive hydrogels along the walls of the microchannels (Fig. 23.8). 

On-wafer membrane deposition and patterning is an important aspect of the fabrication of planar, silicon based (bio)chemical sensors. Three examples are presented in this paper amperometric glucose and free chlorine sensors and a potentiometric ISRET based calcium sensitive device. For the membrane modified ISFET, photolithographic definition of both inner hydrogel-type membrane (polyHEMA) and outer siloxane-based ion sensitive membrane, of total thickness of 80 pm, has been performed. An identical approach has been used for the polyHEMA deposition on the free chlorine sensor. On the other hand, the enzymatic membrane deposition for a glucose electrode has been performed by either a lift-off technique or by an on-chip casting. 

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