For over half of century, the technology of microelectronics has been advancing by miniaturization, leading to significant increases in computing power and continuous decreases in manufacturing cost. In parallel, remarkable progress on enlarging system scale in recent years gives rise to a nascent field known as macroelectronics, in which microelectronic devices are distributed yet integrated over large area substrates with sizes much bigger than semiconductor wafers.
Currently, the macroelectronics industry is dramatically growing in the similar way as the microelectronics was in early ’90s. The most visible example of macroelectronics at present is flat-panel displays, which have been rapidly replacing cathode-ray tubes as the monitors of choice for computers and televisions since 2000. The flat-panel displays have enabled applications unimaginable for cathode-ray tubes. For example, the Dolphins Stadium in Miami will soon have the world’s largest high definition video display, about 15 m high and 42 m wide, comprising more than 4.6 million light-emitting diodes, showing image of more than 1.5 million pixels.
While the commercial success of flat-panel display opens an era of large area electronics, other emerging applications, such as rollable display, printable thin film solar cell and electronic skin, demonstrate further desirable attributes for macroelectronic systems, including flexibility, portability and low-cost. To realize these attributes, a growing trend is to fabricate macroelectronic products directly on flexible substrates, such as polymers. The flat-panel displays currently available in market are fabricated on glass substrates and are fragile. A case in recent news is the cracking of the screens of the iPod nano, a music player that Apple Computer expects to be its best-selling portable device. By contrast, displays made on thin polymer substrates are rugged. Flexible displays of large areas will be lightweight and can be rolled up – they will be portable. For example, in Sept. 2005, Philips Polymer Vision has revealed the world's first prototype of a rollable electronic reader, which can unfold to a 5-inch display and roll back into a pocket-size (100×60×20 mm) device. Furthermore, such thin-film devices on flexible polymer substrates can lend themselves to low-cost fabrication process (i.e., roll-to-roll printing), resulting in lightweight, rugged and flexible macroelectronic products.