(from the book Applied Evolutionary Algorithms in Java)
On of the most exciting developments in EA systems has been the development of hardware that directly supports evolution-based search algorithms. In particular, the availability of Field Programmable Gate Arrays (FPGA) chips allows real-time configuration of logic circuits that can evaluate a specified function (Thompson, 1996) Work at Sussex University by Adrian Thompson demonstrated that a FPGA device could be automatically configured using a genetic algorithm to solve a signal processing problem. This work open an entirely new domnain for tha application of evolutionar algorithms in two important ways: first by showing how reconfigurable hardware could allow improve processing of an EA problem; and second by showing that evolution could exploit the actual physics of a synthetic environment.
Thompson draws some fascinating conclusions regarding the power of such techniques:
A surprising hypothesis is suggested: Even within robust digital design, unsconstrained evolution can produce cirsuits beyond hte scope of conventional design rules. Previously it had been assumed that the domain of robust digital design was fully covered by conventional design rules. Given the undoubted utility of robust digitl designs, it is an exciting possibility that evolution could explore novel regions of design space, containing circuits that may be better for some applications
The main difficulty in utilising an EA technique, however, is the sensitivity of the evolved design to the exact environmental conditions under which it was evolved. For example, the resulting ciruit is normally sensitive to temperature. Further work from Thompson has aimed to enhance the robustness of this process by evolving circuits across a range of temperature values.
The emerging field of evolvable hardware, in FPGA devices, is particularly exciting as it enables the possibility of real-timne learning by EA systems. It also opens an entirely new domain of physical evolution in synthetic substrates, which take advantage of the actual ohysics of electronic systems. Providing such systems can achieve robust solutions, then it cpuld lead to entirely new classes of hardware, which fully exploit the capabilities of the silicon substrate; including their application to evolving analogue electronic devices. (NASA has been particularly interested in the possibilities offered by this technology and has arranged a series of workshops on Evolvable Hardware)