Hydrogel Actuator

Geiger, E. J., Pisano, A. P. and Svec, F. (2010) A polymer-based microfluidic platform featuring on-chip actuated hydrogel valves for disposable applications . Journal of Microelectromechanical Systems, 19,944-950. 

Morales D, Palleau E, Dickey MD, Velev OD (2014) Electro-actuated hydrogel walkers with... 

Yadavalli V.K., Koh W.-G., Lazur G.L., Pishko M.V., Microfabricated protein-containing poly(ethylene glycol) hydrogel arrays for biosensing, Sensors Actuators B 2004 97 290-297. 

The hydrogel of perfluorosulphonate ionomer is also an effective electroactive material. This material already shows actuating properties as a film of 0.2mm in a DC field, with application of only 3 V16. The principle of the deforming mechanism is similar to that for other polyelectrolyte gels. The response time and durability are much better than for... 

The first application developed for smart hydrogels was somewhat mundane. They were used as a liner for golf shoes and in-line skates that takes the shape of the wearer s foot as the result of heat released by the foot, but researchers have envisioned a much broader and more significant number and variety of applications for such materials. Proposed applications include optical shutters actuators and sensors for chemical, heat, and electrical systems valves chemical memory systems fluid switches absorbents for chemical and petroleum spills diapers cosmetics and desalination systems. Thus far, however, the greatest interest has been in biomedical applications of hydrogels. 

Hydrogel valves were also created within microfluidic channels to provide fluid control (see Figure 3.28). The swelling and contraction provide valve-close and valve-open actuation, respectively, due to chemical stimuli (e.g., pH change). To increase the mechanical stability, the hydrogel was formed around prefabricated posts in the channel. Since the thickness of hydrogel is reduced, the response time to chemical stimuli was also reduced to 8 s (from 130 s). When acrylic acid... 

Harmon, M.E., Tang, M., Frank, C.W., A microfluidic actuator based on thermo-responsive hydrogels. Polymer 2003, 44, 4547M556. 

Gerlach G, Arndt KF (eds) (2009) Hydrogel sensors and actuators engineering and technology. Springer, Berlin... 

Abstract In order to tailor hydrogels for the application as actuator-sensor microsystems based on the responsive behaviour of smart gels, a general strategy has to be developed. Since the phase transition phenomenon of hydrogels is theoretically well understood advanced materials based on the predictions can be prepared. The requirements for applying hydrogels can be summarized as follows ... 

Although polymerization of NIPAAm has been extensively investigated in the past using free radical initiator, this method can not be used for the preparation of thin films. Thin hydrogels films can find applications as microfluidic devices for sensors and actuators in case patterning is possible. This problem can be solved by preparing gel films from narrowly distributed microgel particles (Zhou and Wu... 

The swelling behaviour of smart hydrogels makes them very attractive for (micro-) actuator and sensor applications. One key point in the employment of smart... 

Harmon ME, Tang MF (2003) A microfluidic actuator based on thermosensitive hydrogels. Polymer 44 4547 556... 

Lesho MJ, Sheppard NF (1996) Adhesion of polymer films to oxidized silicon and its effect on performance of a conductometric pH sensor. Sens Actuators B 37 61-66 Licea-Claverie A, Salgado-Rodriguez R, Lugo-Medma E, Amdt K-F (2008) Incorporation of acid polymethacrylates into temperature sensitive hydrogels using electron beam irradiation. Polym Bull 60 701-712... 

The application of smart hydrogels in actuator or in sensor systems is possible, even if the response of the degree of swelling and other gel properties on the environmental condition is continuously. For applications it is important that the gel properties are in a strong correlation to the properties of the surrounding liquid phase. 

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