Vs- comes a big price tag because big displays are still made by the same expen- sive photolithography techniques as the diminutive silicon chip. What is needed is a completely new manufacturing approach that will dramatically lower the cost. Polymeric, or plastic, semiconductors provide an exciting opportunity to solve the problem. Polymers can be dissolved in a liquid, thus creating a semi- conducting ink. This ink can be printed using the same technology that is used in jet printers that print documents. Printing has a low cost compared with photolithography for manufacturing of electronics because both material deposition and patterning are done simultaneously. Enormous progress has been made in recent years to develop plastic semiconductors that have electronic properties suitable to drive a display. High-speed, reproducible, and reliable processes, such as roll-to-roll display manufacturing, are also proving effective in the fabrication of light-emitting polymers (LEPs). By using ink-jet printing and the silk screening of organic THE CRITICAL LAST INCH-INPUT AND OUTPUT TECHNOLOGIES materials, LEPs are able to reduce manufacturing cost through effective mate- rial utilization. "LEPs offer all the advantages of small-molecule technology such as low- power consumption and low-drive voltages," says Joe Constance, an analyst at Technical Insights, a technology research company located in San Antonio, Texas. "LEP devices can generate sharp light output, or resolution, and can be fabricated cost effectively in high-pixel density configurations," he adds. Efficient control over structural order in LEPs is required to have an edge over traditional liquid crystal displays. In this regard, polymers that have dif- ferent band gaps may prove to be a key factor in outplaying competing tech- nologies. Emission of red, green, or blue light is possible with different bands, making full-color displays with conductive LEPs commercially viable. Intense research in this area has enabled poly-phenylene vinylene (PPV) to emit blu