Biological systems regularly achieve coherent, reliable and complex behavior from the cooperation of large numbers of identically programmed agents. For example, during development cells with identical DNA cooperate to form complex structures, such as ourselves, with incredible precision and reliability in the face of constantly dying and replacing parts.
As we build engineered systems with large numbers of similar parts, sensors and actuators and computing elements, we expect to see variations in everything from sensing to clocks and unreliable elemnts. At the same time biology hints that there may be significant power to be achieved from building things out of cheap, imprecise, parts with limited life.
The ability to engineer complex but reliable systems from millions of simple and unreliable parts, provides an tantilizing alternative to our current methodologies that rely heavily on making the individual pieces never fail.
In their review article , "Measuring dimensions: the regulation of size and shape". Day and Lawrence present several intriguing examples of how many systems regulate both size and proportions, compensating for large variations in cell size, cell numbers, cell division rates and development time. Houchmandzadeh et al  have shown that early patterning Drosophila is robust and precise inspite of large fluctuations in the concentrations of gradients that set up the early psoitional information in the embryo. Each of these examples hints at powerful underlying mechanisms that are robust to such variations - mechanisms for robustly creating structure that adapt to errors, while maintaining constraints that may be geometric, topological and/or functional. However even within developmental biology community little is know about how size and shape are maintained, let alone how they are robust to such drastic changes.
The goal of this project is to use biology as an inspiration for a robust engineering mechanism. Possible projects could be:
 "Measuring dimensions: the regulation of size and shape", Day and Lawrence, Review Article, Development 127, 2977-2987, 2000.
 "Establishment of developmental precision and proportions in the early Drosophila embryo", Houchmandzadeh, Wieschaus, Leibler, Nature, vol 415, feb 2002.