Embryonics

A human being consists of approximately 60 trillion (60x10^12) cells. At each instant, in each of these 60 trillion cells, the genome, a ribbon of 2 billion characters, is decoded to produce the proteins needed for the survival of the organism. This genome contains the ensemble of the genetic inheritance of the individual and, at the same time, the instructions for both the construction and the operation of the organism. The parallel execution of 60 trillion genomes in as many cells occurs ceaselessly from the conception to the death of the individual. Faults are rare and, in the majority of cases, successfully detected and repaired. This process is remarkable for its complexity and its precision. Moreover, it relies on completely discrete information: the structure of DNA (the chemical substrate of the genome) is a sequence of four bases, usually designated with the letters A (adenine), C (cytosine), G (guanine), and T (thymine).

Our Embryonics project (for embryonic electronics ), situated on the ontogenetic axis of our POE model , is inspired by the basic processes of molecular biology and by the embryonic development of living beings. By adopting certain features of cellular organization, and by transposing them to the two-dimensional world of integrated circuits on silicon, we will show that properties unique to the living world, such as self-replication and self-repair, can also be applied to artificial objects (integrated circuits).

Objectives and Strategy

Our final objective is the development of very large scale integrated (VLSI) circuits capable of self-repair and self-replication . Self-repair allows partial reconstruction in case of a minor fault, while self-replication allows complete reconstruction of the original device in case of a major fault. These two properties are particularly desirable for complex artificial systems in situations which require improved reliability, such as :

• Applications which require very high levels of reliability, such as avionics or medical electronics.
• Applications designed for hostile environments, such as space, where the increased radiation levels reduce the reliability of components.
• Applications which exploit the latest technological advances, and notably the drastic device shrinking, low power supply levels, and increasing operating speeds, which accompany the technological evolution to deeper submicron levels and significantly reduce the noise margins and increase the soft-error rates.
• Applications that will need to be executed flawlessly on highly-flawed substrates, such as the future nano-electronic devices, whose characteristics will be very close to those of living organisms.

These emerging needs require the development of a new design paradigm that supports efficient online testing and self-repair solutions. Drawing inspiration from the architecture of living beings, we wish to show how to implement online testing, self-repair, and self-replication using both hardware and software redundancy.

Approach

Within the Embryonics project, we have been studying the application of biological ontogenesis to the design of digital hardware for several years. Among what we feel are our main contributions to the field is a self-contained representation of a possible mapping between the world of multi-cellular organisms in biology and the world of digital hardware systems, based on 4 levels of complexity, ranging from the population of organisms to the molecule. Within this mapping, we define an artificial organism as a parallel array of cells, where each cell is a simple processor that contains the description of the operation of every other cell in the organism in the form of a program (the genome). For a given application, all cells are structurally identical and contain the same program (and can thus be seen as stem cells), but different parts of the program and of the structure are activated depending on the cell's position within the array, implementing cellular differentiation. Moreover, our cells are application-specific, that is, are structurally and fuctionally adapted to the application to be executed, again in keeping with our biological inspiration (a skin cell is physically different from a liver cell). To achieve this property, we redefined our cells as reconfigurable processing elements, realized by custom programmable logic circuits (FPGA) that fulfil the role of molecules in our system. Dedicated hardware within our FPGA implements special features, such as growth, adaptation, and self-repair, that are both highly unusual in computing devices and potentially useful in view of the latest technological advances.

Contacts:

Prof. Daniel MANGE

Prof. Gianluca TEMPESTI

Key publications:

• D. Mange, M. Sipper, A. Stauffer, G. Tempesti. "Towards Robust Integrated Circuits: The Embryonics Approach". Proceedings of the IEEE, vol. 88, no. 4, April 2000, pp. 516-541.