Self-healing mechanism

A highly relevant question is whether the goal should be to operate at the level of the single component or not. In order to minimize the risk of device failure the incorporation of some redundancy or repair procedures appears unavoidable, as in biological processes, so that it will be necessary to develop suitable addressing and detection procedures, error-checking and self-healing mechanisms for multidevice arrays. 

In other words, they have a self-healing mechanism. One major characteristics of supra-molecular structures is this capability for self-processes. There are processes that occur spontaneously, but they don t occur for covalent bonds at normal temperatures and pressures because they are too stable for that. You may in this respect consider molecular chemistry as stable chemistry or fixed-structure chemistry, and supramolecular chemistry as fluid chemistry. The term fluid here means that the structures can be arranged and rearranged, assembled and disassembled depending on the surroundings. Adaptation is another important characteristics of supramolecular systems. A molecular structure, as far as connectivity and gross change is concerned, is very stable, not influenced so much by the medium. A supramolecular structure can, in principle, adapt to the medium. 

Figure 1.52 Self-healing mechanism ofTa capacitors.

Q. Ludovic, R. Francis, G. Alain, T. Flenri, and L. Caroline, Self-healing mechanisms of a SiC fiber reinforced multi-layered ceramic matrix composite in high pressure steam environments, J. Eur. Ceram. Soc. 27[4], 2085-2094(2007). 

If a double layer is deformed by any kind of stress, which causes a reduction of density of surfactant molecules, this area has a higher surface tension (and higher energy). The system tries to compensate by a) migration of surfactant molecules from the bulk liquid into the area and b) shift of molecules from the double layer into the region. By this means, the system stabilises itself This self-healing mechanism is also known as the Marangony-Effect" ... 

Zheng P, McCarthy TJ (2012) A Surprise from 1954 siloxane equilibration is a simple, robust, and obvious polymer self-healing mechanism. J Am Chem Soc 134 2024... 

The oxide film grown in this process has a thickness of 0.5 pm. It is a film of a zinc oxide/hydroxide containing different chromium oxides (CrO(OH), Cr20j, Cr205, CrOj) and zinc chromate (ZnCrO ). The chromate ions are rather mobile. If a zinc layer on a steel substrate gets a scratch somewhere on the zinc, the chromate will diffuse to this scratch and repassivate the surface (the self-healing mechanism). ... 

Aramaki K. Self-healing mechanism of an organosiloxane polymer film containing sodium silicate and cerium (111) nitrate for corrosion of scratched zinc surface in 0.5 MNaCl. Corrosion Science, 44(7), 1621-1632 (2002). 

Standard Mn02 electrode system feature a self-healing mechanism that provides efficient process that re-cover defects in the dielectric. 

Harada, D. 1997. Self-healing mechanism of Neo-capacitor, NEC Research Development, 38, (3), pp. 301-305. 

The above-mentioned properties of metallopolymers are the basic requirements for the generation of self-healing behavior. As a consequence, it is possible to generate a reversible system and to introduce self-healing mechanisms, which is the principle of intrinsic self-healing systems [78-81]. 

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