By David Pescovitz
Small Times Columnist

July 25, 2003 Ð Imagine your kitchen blender conks out the day you're hosting a large cocktail party. You search an online catalog, decide on a model, and click the "buy" button. But instead of waiting three days for the appliance to be shipped to your door, a new kind of printer on your desk springs into action. Layer by layer, the miraculous machine squirts out various materials to form the chassis, the electronics, the motors --literally building the blender for you from the bottom up in a matter of hours.

Call it desktop manufacturing. For gadget geeks in need of instant gratification, it's a miracle. For designers deep in the iterative prototyping process, it's a revolution in product development. And thanks to small tech, it's becoming a reality.

University of California, Berkeley engineering professor John Canny and his colleagues are building such a printer. They call the technology "polymer mechatronics" or, more simply, flexonics. The revolutionary approach to desktop manufacturing is enabled by recent advances in 3-D printers, organic electronics and polymer actuators.

Three-dimensional printers are commonly used to make prototypes of new product designs. For example, a designer may load a digital design into a Fused Deposition Modeling machine. The FDM then extrudes thin beads of ABS plastic in .01-inch layers, until you have a completed passive functional part or device. While the printers are dropping in price, the leap from producing passive to active devices is monumental. That's where organic electronics come into play.

Organic electronics were born in the 1970s when researchers discovered that chemically doping organic polymers, or plastics, increases their electrical conductivity. Since then, researchers have worked to develop the most effective and inexpensive organic compounds that can be patterned on flexible substrates to create useful circuits. In the private sector, companies ranging from Bell Labs to IBM to UK startup Plastic Logic are also working to develop quality organic transistors that are fabricated far more cheaply than silico