Switching bistable

The results are shown in Figure 2. Spectra are plotted for various values of normalised input intensity yinc = n2 inc which can be considered as the strength of the nonlinearity. A positive nonlinearity, yjnc > 0, that shifts the spectra to the right was used. As expected the nonlinearity (spectral shift) is enhanced with increasing number of the periods. Moreover the structures with 2 and 3 periods exhibit bistable behavior for A, > Aq. In this case bistable switching is controlled by frequency tuning while input intensity is fixed. 

Heintz RA, Zhao H, Ouyang X, Grandinetti G, Cowen J, Dunbar KR (1999) New insight into the nature of Cu(TCNQ) solution routes to two distinct polymorphs and their relationship to crystalline films that display bistable switching behavior. Inorg Chem 38 144—156... 

The fabrication of active semiconductor devices from amorphous semiconductor films is a further application that offers considerable advantages. Thin-fihn transistors, based on amorphous films of hydrogenated silicon, are nnder intensive development. Other devices with monostable and bistable switching characteristics have also received considerable interest. Naturally enough, the performance of snch devices is intimately related to the transport properties of charge carriers in the materials employed. 

Thermally or photochemically induced proton transfers represent bistable switching processes and are of interest for information storage. A lateral transfer of information on the surface of biological membranes is thought to occur by fast proton conduction through protonic networks [8.234]. 

In general, optically, electrically or chemically triggered switches would seem to be preferable to mechanically activated ones, as are photo-, electro- and chemo devices with respect to mechano devices and electronic or photonic computing with respect to mechanical computing. The ultimate in (nano)mechanical manipulation of a molecular device is represented by the realization of a bistable switch based on the motion of a single atom by means of the scanning tunnelling microscope [8.295] (see also Section 9.9). 

Figure 16. Plot of the conductivity of aerosol-OT (A-OT) samples vs. 1/a where d is the lamellar repeat distance (38). Samples with 65.1% A-OT were sometimes bistable, switching between high and low conductivity.

In solid state all the 10 pyroelectric crystal groups allow in principle for bistable switching behaviour. This is the proper ferroelectricity. Under certain conditions ferroelectricity (improper) can be realized in liquid crystals. This was shown by Meyer and coworkers115 in 1975. Since that time intense activities have been initiated, applying this property for flat-panel devices, switches, light modulators etc. In principle, three effects can be observed and used ... 

One rotaxane molecule is shown in Figure 5.9. This molecule is not expected to demonstrate bistable switching, but is a candidate for a molecular switch that can be configured one time. Note that both ends of the molecule are non-polar hydrocarbon moieties while the center of the molecule is polar. Molecules that have both a non-polar and a polar end, for easier formation of Langmuir-Blodgett films, have been synthesized and tested in devices.51... 

One possible application for low complexity electronics is radio fi equency identification-tags (RFID) for example in the food or drug packaging industry. In addition, for economic reasons the low cost electronics system should be able to operate without a permanent power supply. Many organic materials not only show conducting or semi-conducting but also bistable switching behaviour. 

The application of bR as protein biochip offered a new possibility in the molecular memory research. As an example of current work, consider the molecular optical memory research underway by Birge and coworkers. Using the purple membrane from the bacterium Halobacterium hajobium, a working optical bistable switch, fabricated in a monolayer by self-assembly, that reliably stores data with 10,000 molecules per bit was realised. The molecule switches in 500 femtoseconds and the actual speed of the memory is currendy limited by how fast you can steer a laser beam to the correct spot on the memoty. 

However, the bistable switching was not reported in Omenat et al. s FLC-coil block copolymers [79]. We speculate that it may be due to a relatively small LC segments and small domain sizes in their system. Ober et al. have prepared a FLC-coil diblock copolymer and demonstrated its bistable switching behavior using the concept of MSFLC [109, 130] although their system is far from practical application due to the slow response time (=0.1 s) and high volt-age (Vpp=700 V/10 jim cell) needed for the bistable switching. 

As the work of Ozbudak et al. and Vilar, Guet and Leibler on the lac operon demonstrated, abstract kinetic models with a few variables are sometimes sufficient to capture the essential behavior of the system, e.g., the bistable switch in the lac operon. Some arbitrariness may seem to exist in how these simple lac operon models were generated, because they seem to look very different and the dynamical variables are not the same. However,... 

R. Barberi, M. Giocondo and G. Durand, Flexoelectrically controlled surface bistable switching in nematic hquid crystals, Appl. Phys. Lett. 60(9), 1085-1086, (1992). doi 10.1063/1.106452... 

Paito, S.P., Bamik, ML Bistable switching of nematic liquid crystal layers with ground 2tt-state. Zh. Eksp. Tetu. Fiz. 127,220-229 (2005)... 

Palto, S.P., Geivandov, A.R., Bamik, M.I., Blinov, L.M. The new role of alignment layers in bistable switching of ferroelectric liquid crystals. Numerical simulations and experimental results. Ferroelectrics 310, 95-109 (2004)... 

Enhancement in Response Speed of Bistable Switching for Composites of Liquid-Crystalline Polymers and Low-Molecular-Weight Liquid Crystals... 

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