The main requirement for the basic element of novel computing hardware is a physical element that we can make work as an operator (special case: binary operator) that takes 2 or more inputs and produces consistent output according to the laws it follows.
For example, Transistor, which acts as the basic element of current-generation computers, acts as a binary operator with its three terminals.
Whatever the hardware
- DNA or otherwise
the basic element from which the computer is built, has to act as an operator.
- One is that the operator, implemented as a physical element, has to work really fast; faster than the switching time of current generation transistors. Otherwise, why would we leave silicon-based transistors behind?
- And the element has to be really small. Otherwise, how would you pack billions of elements required to build the computer in a small space?