Motion peristaltic

Micropumps based on piezoelectrics are made of pumping chambers that are actuated by three piezoelectric lead zirconate titanate disks (PZT). The pump consists of an inlet, pump chambers, three silicon membranes, three normally closed active valves, three bulk PZT actuators, three actuation reservoirs, flow microchannels, and outlet. The actuator is controlled by the peristaltic motion that drives the liquid in the pump. The inlet and outlet of the micropump are made of a Pyrex glass, which makes it biocompatible. Gold is deposited between the actuators and the silicon membrane to act as an upper electrode. Silver functions as a lower electrode and is deposited on the sidewalls of the actuation reservoirs. In this design, three different pump chambers can be actuated separately by each bulk PZT actuator in a peristaltic motion. 

Berens [7] reported that under such conditions the logarithm of diffusivity is a linear function of the molecular diameter of the penetrant molecule. This is consistent with the hypothesis discussed in detail by Stern and Frisch [8, 9] that diffusion through a rigid polymeric matrix is proportional to the energy required to expand (i.e. swell temporarily on a molecular scale) the polymeric chains sufficiently to allow peristaltic motion of the penetrant molecules along these chains. This energy is presumed to be proportional to the molecular diameter of the penetrant. 

Ru(bpy)3) solution, (b) Periodic redox changes of the miniature poly(NIPAAm-co-Ru(bpy)3) gel (lower) and the swellingdeswelling oscillation (upper) at 20°C. (c) Time course of peristaltic motion of poly(NIPAAm-co-AMPS-co-Ru(bpy)3) gel in a catalyst-free BZ reaction solution. 

Self-Oscillating Gel Conveyers Autonomous Mass Transport Surface Using Peristaltic Motion of the Gels... 

To construct an autonomous mechanical pumping system such as intestines, we fabricated a self-oscillating gel in a tubular shape by photopolymerization (Fig. 5.1.4) [50]. Several types of tubular self-oscillating gels that exhibit autonomous peristaltic motion were... 

FIGURE 5.1.5 (a) Schematic illustration of autonomous pulsatile flow by peristaltic motion of a tubular self-oscillating gel. (b) Distribution of the velocity vector in the tubular self-oscillating gel during the autonomous peristaltic motion. 

One of the recent topics in this area involves stimuli-responsive gels, under the descriptive title of self-walking gels, wormlike motion of gels, and peristaltic motion of gels. ... 

Maeda, S. Kara, Y Yoshida, R. Hashimoto, S., Peristaltic Motion of Polymer Gels. Angew. Chem. Int. Ed. Engl. 2008,47, 6690-6693. 

For the stomach as well as for the esophagus, luminal distention, reduction of peristaltic motion and an optimal distribution of residual fluids are mandatory in order to obtain high quality 3D datasets (Lee and Ko 1996a, 1999 Kim SH 2005). The required contrast difference between the gastric wall and its lumen can be enhanced by ingestion of positive or negative contrast materials. 

The contact half-width, b, can be calculated from the Hertz contact theory by using the actual values of physical property for the loaded gel and the gel sheet such as Poisson ratio, the Young modulus, etc. As a result of calculation from the above equation, the minimum inclination angle was 3° and it was the same as the angle resulted from the experiment. It was found experimentally and supported by the model that the sheer wave fl ont of the peristaltic motion was necessary to transport cylindrical gels. 

Murase, Y Maeda, S. Hashimoto, S. Yoshida, R. Design of amass transport surface utilizing peristaltic motion of a self-oscillating gel. Langmuir 2009, 25, 483 89. 

Murase, Y. Hidaka, M. Yoshida, R. Self-driven gel conveyer Antonomous transportation by peristaltic motion of self-oscUlating gel. Sensors Actuators B-Chem. 2010,149, 272— 283. 

The peristaltic pump consists of a series of rollers around a central axis. Plastic tubes are held against the rollers by clamps so that as the central axis rotates, the tubes are alternately compressed and released. Solutions are thus forced through the tubes in the same way that the contents of the intestine are forced along by peristaltic motion. Figure 3.5 shows a typical pump. 

Peristaltic Motion of Cels with Propagation of Chemical Wave... 

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