Consider the specifications of a book. It:

• boots instantly
• has a high-contrast, high-resolution display
• is viewable from any angle, in bright or dim light
• permits fast random access to any page
• provides instant visual and tactile feedback on the location
• can be easily annotated
• requires no batteries or maintenance
• is robustly packaged

A laptop meets exactly none of these specifications; if the book had been invented after the laptop it would have been hailed as a breakthrough in information technology. Rather than discard these many virtues, we're discovering that it's possible to print with optically and electrically active materials to create books that can change their contents, merging the beauty and convenience of ink and paper with the malleability of the digital world.

Accomplishing this is just one of the revolutionary projects in PennyPC (PPC), a new research effort at the MIT Media Laboratory that is developing commodity processes (like printing) and natural mechanisms (like smart materials) to dramatically reduce the cost and improve the performance of computation and communications.

If information technology is viewed as a pyramid, from million-dollar mainframes down to thousand-dollar PCs, at the bottom are smart-cards for dollars, and RFID chips for ten of cents. The economics of this relatively neglected base leaves off most of the world. Electronically tracking inventory, automatically personalizing services, eliminating retail checkout, or monitoring healthcare delivery are unlikely to succeed if the cost added to a product exceeds the price of manufacturing the product. These applications require determining the identity of an object, tracking its location, and sensing and displaying its state, for costs reaching below pennies per tag. While VLSI scaling has brought an exponential reduction in the cost per transistor in a chip, the minimum cost per packaged part has changed little from the earliest days of electronics. Bringing computing and communications out to where people live and business is transacted is going to require going beyond today's technologies to develop fundamentally new ways to manipulate information that take advantage of the latent capabilities of physical systems.

The enabling research in PPC to accomplish this includes:

This effort is developing a suite of chemistries that can be used in both desktop and high-speed roll-to-roll processes to print logic, interconnect, memory, sensing, communications, and displays on paper-like substrates. Along with replacing conventional chip fabs, this promises to permit fabrication to be done on significantly larger substrates, and to move the means of production from centralized fab plants out to personal printers that can be used where and when they are needed. One of the dreams of this project is "radio paper," a sheet of paper with a display, solar cell, and radio receiver printed on it so that the contents are always current. An early success has been the development of micro-encapsulated electropheretic systems for electronic inks.

By printing with mechanically as well as electrically active materials, it becomes possible with a table-top process to output working three-dimensional objects that integrate physical and logical function. This has already been demonstrated in all-printed motors. Existing MEMS application use billion-dollar fab plants to make structures with micron-sized features; PEMS seeks to do for fabrication what the PC did for computing by permitting the customized creation of macroscopic objects. From a working child's toy to a kitchen appliance to a medical diagnostic probe, these things should be built on demand to meets the needs of the user rather than the conception of the designer. Along with developing the necessary chemistries, this project is addressing the means for material placement, and the higher-level description of the structures (leading towards an "ATML", Atomic Mark-up Language).

RFID chips are presently used to embed a remotely-sensed identity into objects that need tracking, but for many applications they cost too much, their packaging requirements are incompatible, or their functionality is too limited. This project is exploring printable chemistries, and material mechanisms, to eliminate the need for conventional circuitry entirely. Electromagnetically active structures are being developed across the spectrum from screened electrostatic coupling to far-field propagation, along with programmable nonlinearities to enlarge the code space for channel sharing, and modification of the response by the local environment to merge sensing and position measurement into the remote interaction. Reader instrumentation is being developed along with the materials, to bring them out of the laboratory. The applications being prototyped range from "RFIP", embedding a remotely-read Internet address into commodity products, to molecular computation, using the evolution of a nuclear spin system for information processing.

Making computing invisible by merging the bits of the digital world with the atoms of the physical world, as PPC seeks to do, will be useless unless the logical information can be as intuitively accessible as the physical information. This is why an important component of PPC is studying the attendant interface issues, merging questions of industrial design, graphical design, and user interface design into a new notion of a tangible user interface.

PPC is one of a number of "Special Interest Groups" that have grown out of the larger research Consortia in the Media Lab (Things That Think - moving computing out of traditional computers and into the world around us; News In The Future - gathering, transforming, and delivering timely information; Digital Life - how people live in a world of electronic information). Each of these Consortia brings together about 50 companies and 10 faculty members to address broad themes across industries and disciplines. Membership in a Consortium is $200k/year, and provides royalty-free rights to all work done in the Media Lab. This commitment is on the order of one person-equivalent distributed over the Media Lab (actually comprising the work of about 400 people with a $30M/year budget). Membership in PPC for an additional $75k/year provides a way to go beyond the Consortia to support expanded activities in areas of interest to a company, have a stronger role in guiding the work, and help shape early technology transfer from the program to the sponsor.

The sponsor representatives who participate in the work of PPC mirror the mix of disciplines that contribute to the research: physics, chemistry, materials, algorithms, as well as a number of application domains. Unlike the more heterogeneous Consortium meetings, the semiannual PPC meetings provide an apportunity for this group to delve into much greater technical detail in the underlying research. Among the industries represented are chemistry and paper companies looking to add value to their commodity products, biomedical companies seeking smarter healthcare delivery, media organizations trying to marry the strengths of traditional media with the potential of new channels, technology companies moving towards mass markets, and firms already in competitive consumer markets trying to add intelligence to their products. The number of members is limited to preserve the focus and close working relationships of this group.

The problems being addressed in PPC are central to making information technology less obtrusive and more responsive to the needs of the world, from mature industries to developing countries, from senior executives to inquisitive children.