US Patent 7187201 - Molecular programmable logic

http://www.freepatentsonline.com/7187201.pdf

Xilinx is the leading company in programmable logic devices which typically work by using an arrays of logic circuits (NAND, NOR, etc.) and fuses (or anti-fuses) which can be programmed to achieve a desired logical function. This patent proposes the use of switchable molecules such as rotaxane to achieve programmable logic. Claim 1 reads:

1. A circuit comprising: a programmable cross-wire interconnect, the programmable cross-wire interconnect including: a first plurality of wires; a second plurality of wires oriented with respect to the first plurality of wires so that a first one of the first plurality of wires crosses a first one of the second plurality of wires at a non-zero angle to form a programmable junction; wherein the programmable junction includes a first molecule coupled between the first one of the first plurality of wires and the first one of the second plurality of wires; and wherein the first molecule has a first energy state and a second energy state; a logic device including an input terminal and an output terminal, wherein at least one of the input terminal and the output terminal is coupled to the first one of the first plurality of wires; and at least one of a pullup device and a pulldown device coupled to the logic device, wherein the at least one of a pullup device and a pulldown device includes a second programmable junction formed between the first one of the first plurality of wires and a third wire, wherein the second programmable junction includes a second molecule coupled between the first one of the first plurality of wires and the third, and wherein the second molecule has a first energy state and a second energy state.