IPMNCs

Fig. 2.7 Step voltage response displacement characteristics of IPMNC hydrated samples [9]. Smart Materials and Structures 2004, reprinted with permission...

Plate 1 A heart with an IPMNC compression band. (See Figure 7.17)... 

In a previous work, Kim and Shahinpoor [11] have reported a newly developed fabrication method that can scale up or down the IPMNC artificial muscles in a strip size of micro-to-centi-meter thickness, using the liquid form of perfluorinated ionic polymers. By meticulously evaporating the solvent (isopropyl alcohol) out of the solution, recast ionic polymer can be obtained. A number of these samples are shown in Figure 7.3. 

Figure 7.4 A four-fingered IPMNC compression system in open configuration.

Figure 7.6 Displacement characteristics of an iPMNC, ERi-SI (8 arc length, Lo - effective cantilever beam length). Lo— 1.0 inch (top) and Lo= 1-5 inch (bottom).

Figure 7.7 Variation of tip blocking force and the associated deflection if allowed to move versus the applied step voltage for a Wx 50 x 0.3 mm IPMNC Pt-Pd sample in a cantilever configuration.

Figure 7.7 depicts typical force and deflection characteristics of cantilever samples of IPMNC artificial muscles. 

Figure 7.8 A typical voltage response of an IPMNC strip (10x40x 0.2 mm) under oscillatory mechanical excitations.

Figure 7.9 Output voltage due to normal 90° Impact of a 200 N load on a 20 x 20 x 0.2 mm IPMNC sample.

Figure 7.10 Long cycles oscillation of IPMNCs versus blocking force (sample size 5x 20x 0.2 mm). The environmental chamber was maintained atT—25°C and RH — 50-55 %.

It should be mentioned that (1/pc) = M(E)/YI, where M(E) is the local induced bending moment and is a function of the imposed electric field E, Y is the Young s modulus (elastic stiffness) of the strip, which is a function of the hydration H of the IPMNC, and I is the... 

Based on this simplified model the tip bending deflection, max, of an IPMNC strip of length Ig should be almost linearly related to the imposed electric field due to the fact that... 

Application of IPMNCs to Heart Compression and Assist in General... 

In Figure 7.14, again 3 denotes the compression fingers made with IPMNCs, 5 is the heart itself, 4 depicts an encapsulated enclosure filled with water to create a soft cushion for the compression fingers, 4d s are IPMNC based sensors cilia to continuously monitor the compression forces applied to the heart and 3e and 3f are the associated wiring and electronics. Note that, assisting or soft compression of the left ventricle of a weak heart will produce more internal pressure to pump more blood in synchrony with the natural systolic contraction of the ventricle. Additionally, the proposed system will also provide... 

Figure 7.14 Heart compression device equipped with IPMNC fingers.

Specifically, the proposed IPMNC based device will provide entirely electrically-controllable and micro-processor-controlled multi-fingered resilient sphinctering heart compression devices that can be implanted inside the rib cage of a patient with weak heart and will gently squeeze the weak heart to enhance blood circulation and assist the weak heart. Other configurations are depicted in Figures 7.15 and 7.16. 

Figure 7.15 Four-fingered heart compression device equipped with thick IPMNCs (a) before compression (b) after compression.

Figure 7.18 An IPMNC compression band in open and closed configurations.

Figure 7.19 Mini heart compression device equipped with iPMNC muscles.

The preparation of thick IPMNC fingers follows the procedure outlined in reference [38]. However, the reader is referred to references [14-18] for additional information on IPMNCs. 

Thus, thick IPMNC strips were manufactured based on the procedure reported in [37] and subsequently equipped with platinum electrodes and gold plating on both sides of the strip with a particle penetration depth of 20 mm. Photographs of the IPMNC samples with the platinum electrodes covered with the gold electrodes are shown in Figure 7.22. 

It must be mentioned that other types of organ compression, and in particular aortic peristaltic compression to enhance blood circulation and assist a weak heart, are also possible with IPMNC polymeric muscles, as depicted below in Figure 7.23. Furthermore, endoscopic surgical operations with IPMNCs bundled up and insertable through endoscopic incisions is also possible, as depicted in Figure 7.24. 

Figure 7.22 Manufacturing sequence of the heart compression device (a) four IPMNC fingers cut to scale (b) the fingers assembled between two gold ring electrodes (c) the fingers placed between the ring electrodes and closed.

Fi re 7.23 IPMNCs configured to perform peristaltic compression on aortic blood flow and enhance blood circulation and assist a weak heart. 

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