Kinematic Self-Replicating Machines
© 2004 Robert A. Freitas Jr. and Ralph C. Merkle. All Rights Reserved.
Robert A. Freitas Jr., Ralph C. Merkle, Kinematic Self-Replicating Machines, Landes Bioscience, Georgetown, TX, 2004.
4.14 Zyvex Nanomanipulator Array Assembler System (1997-1999)
An early assembler system design appeared on the Zyvex Corp. website during 1997-1999 , and in a different version in 2000 , and read, in part, as follows:
“Our idealized assembly process starts from a Computer-Aided Design (CAD) description of some object to be built. Computer-Aided Manufacturing (CAM) software decomposes the object into primitive building blocks and then into an assembly sequence. The assembler control computer uses this assembly sequence to control a huge number of nanomanipulators performing mechanochemistry to build the desired object. Each nanomanipulator may only be capable of moving a single molecular scale building block around, but since there are a huge number of these nanomanipulators working simultaneously, the system is capable of building a large quantity of products.
“The assembler differs from both semiconductor manufacturing and bacteria in that it operates on some atomically precise molecular building blocks to build precise structures of arbitrary complexity, as specified by a CAD/CAM program. Very simplistically, it could be a bank of molecular-scale robotic arms with chemical binding sites on some arms, and grippers to hold components being built on another set of arms, all under the control of an outboard computer instructing it how to move to snap together the building blocks for the desired product. The assembler control computer totally controls the product being built, driving the manipulators to execute the sequence of motions specified by the manufacturing software. In the morning, this assembler might make computer memory modules; in the afternoon, it might make medical manipulators; later it might be programmed to build power storage devices.
“The initial assembler will not include an onboard computer or power source for the manipulator, so must be controlled and powered from outside the device. The system design required for a practical assembler must deal with how to get power and signal into a huge number of nanomanipulators, as well as how to get feedstock to them and take finished materials away after construction. [One] approach would be to anchor nanomanipulators on a substrate that could provide power, control, and a transport system for materials. Such a system could move a large number of manipulators by moving the substrate, and thus could build objects much larger than itself in all dimensions.
“This first assembler can be a crude device; its purpose is to show that molecular nanotechnology is feasible, and to build a better device. For rapid improvement, the manufacturing system must be capable of being improved by the products it manufactures. A semiconductor manufacturing plant cannot manufacture itself, hence the cost of a semiconductor production line goes up with each generation, and is now nearly unaffordable. A well-designed nanotechnology manufacturing plant should not suffer from this problem, since it will be built using the same technology and techniques it is using to manufacture other goods.
“The last point is important enough to restate. A practical design for an assembler requires the assembler to be made from materials it can handle. With this closure, assemblers can be manufactured as inexpensively as the products they make. This capability is often called self-replication, although we prefer the term exponential assembly, which is less likely to be confused with living entities. Living systems carry their own instructions in DNA, while exponential assembly does not. Exponential assembly devices must receive instructions from a conventional computer control system. This system design is both simpler and safer.”
Last updated on 1 August 2005