Flexible devices

We have adapted a commercially available x-ray diffractometer normally used for structure determinations on single crystals to operate as a very flexible device for performing x-ray pole figure determinations and related studies on polymeric materials. Descriptions of crystallite orientations, as provided by pole figures, are useful in studying many aspects of the behavior of products made from semicrystalline polymers. This paper describes the software that we have written for our pole figure facility. Except for some vendor-provided routines to drive the hardware Interface all of our software is written in FORTRAN. Menu driven operation is provided to maximize user convenience. 

OLED on an Al-PET substrate. The device performance does not deteriorate after repeated bending, suggesting that there is no significant stress-induced change in the characteristics of the OLEDs fabricated on PET foil [71,82]. The results demonstrate the feasibility of fabricating flexible displays using a variety of plastic substrates including metal-laminated plastic foils, or a metal film sandwiched between two plastic foils. The flexible device structures enable a display to conform, bend, or roll into any shape and thus make possible other product concepts. 

These small, flexible devices open up two new monitoring paradigms (1) personal exposure and mobile monitoring and (2) measurements at a multitude of fixed sites which can also be flexibly located in living areas where current monitoring containers cannot be placed. 

With reference to the thermal characteristics of the substrate, and in light of the proposed use of the printed pattern, there may be a need to match the thermal expansion coefficient of the substrate and the dry ink. In addition, for printing of flexible devices, the flexibility of the printed pattern must be adjusted to that of the substrate. 

The ability to vary oxygen enrichment levels instantaneously also provides the cupola or blast furnace operator with an extremely flexible device to control furnace operations better in spite of unavoidable changes in coke and metallic charge quality, blast humidity and temperature, and cast house demand pattern. Today, hundreds of cupola foundries worldwide use oxygen to increase cupola capacity and/or reduce unit operating cost, and most modem blast furnaces are equipped with oxygen injection. 

Recently the idea of Ago et al. to replace the ITO electrode by a CNT based electrode was pursued by several groups again. However, this time SWNTs were used [330-333]. The motivation for this step is generally found in the benefit of replacing an expensive vacuum step in the fabrication of polymer solar cells [330] with roll-to-roll production of supporting nanotube electrodes (Fig. 67) [331], which will aid in the removal of ITO and PEDOT PSS related problems [332] while facilitating applications of flexible devices on plastic substrates [333]. 

Anodization is an intriguing approach to generating controlled thickness dielectric films. Sputtering the metals onto flexible substrates opens up the possibility of flexible devices. Anodization is a low-temperature process that occurs in aqueous solution, which suggests potentially easy processing methods. 

For a poly(parabanic acid) resin as substrate, a6T as semiconductor, and cyanoethylpullulan, a highly flexible device could be obtained which shows no changes in the transistor characteristic after bending and twisting. However, the metallic gate and source electrodes sometimes disconnect. A really pure all-organic FET with a graphite-based polymer ink used to prepare the source and drain contacts does not even show this instability [305],... 

Very recently, a flexible device associating PANI to colloidal tungsten oxide was tested [106], and an all solid-state device PANI/PAMPS(pH4)/W03, 2H2O presented at ICSM 96 was successfully cycled up to 20 000 cycles with interesting values of optical densities [107]. 

Buriak and co-workers investigated the optoelectronic and photophysical properties of region-regular poly[3-(carboxyalkyl)ihiophene-2,5-diyl] donors poly-64 (x = 3-6) with different carboxyalkyl chain length [102]. Each polymer was combined with PCBM as electron acceptor to form the photoactive BHJ layer for OPV devices. The hydrogen bonding formed between the carboxylic units was revealed to be suitable for use in flexible devices. PCE of up to 2.6 % was obtained for poly-64 (x = 5)/PCBM film. 

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