Smart gel

Smallpox vaccine Smalt Smaltite SMA resins SMART Smart catalysts Smart gels Smart hydrogels Smart material Smart materials... 

These four types of forces are responsible for the adaptive behavior of smart gels. The different forces come into play when the network of polymer chains composing a gel is disturbed, (a) Charged ionic regions can attract or repel each other, (b) Nonpolar hydrophobic regions exclude water, (c) Hydrogen bonds may form from one chain to another, (d) Dipole-dipole interactions can attract or repel chains. 

In this Section, we describe two complex deformations due to electric field-associated swellings. One is the bending of a hybrid gel consisting of a PVA-PAA gel rod and a PVA film in dc fields. The hybrid gel has been used to fabricate a smart gel finger. The other is the vibration of PVA-PAA gel film in ac fields. This new deformation suggests a gel having a fast response on the order of 100 ms. 

Sounds and vibrations in electrical appliances or vehicles are in some cases unpleasant. If we can reduce these sounds and vibrations as we desire, we will have a more happy and comfortable life in the next century. Sections 4 and 5 discuss a new smart polymer gel for actively reducing sounds and vibrations. The smart gel can vary its elastic modulus in an electric field. 

The three biomimetic actuator models mentioned above are driven in a solution. The next target of the advanced model is an actuator electrically driven in air. A mechanical hand composed of two smart gel fingers working in... 

Fig. 13a, b. Biomimetic actuators using electric field-responsive gels a robot hand having four smart gel fingers which can hold a quail egg, and b artificial fish with a tail of gel film which can swim under ac electric fields... 

A host of scientists in universities and industrial laboratories are finding that by adding side chains to the crosslinked chains or otherwise altering their structure they can control when and how the materials respond. It is therefore to be expected that they will design new smart gels and ideas for gel-using systems in the future. 

You might actually be stepping on one of these new materials the next time you use in-line skates. One brand of these skates contains a smart gel that is a liquid at normal temperatures but sets to a firm, rubbery gel when exposed to body temperature. The gel fills the space between the lining of the skate boot and the sides, so that once the skate has been secured, it sets to conform to the exact shape of the foot. The gel has gone through a phase transition. 

This sample of a smart gel expands in response to an increase in temperature. 

Tanaka s discovery of smart gels revolutionized many fields of theoretical and applied science. Their behavior provides an insight on the properties of proteins, and they are expected to have a number of practical applications in... 

C to 31°C. Another intelligent gel invented by Sonja Krause and Katherine Bohon at the Rensselaer Polytechnic Institute consists of poly(dimethylsiloxane) and poly(ethylene oxide). This material demonstrates the ability to pulsate back and forth between its expanded and contracted form in less than a millisecond when a small electrical potential is applied to it. Among the most popular materials used to make smart gels are the polymers poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA), poly(acrylonitrile) (PAN), poly(2-hydroxy-ethylmethacrylate), and poly(2-hydroxypropylmethacrylate). 

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