THE GENETICS: Making a system that can duplicate itself without modern life’s elaborate protein enzymes is the project’s biggest hurdle, but progress has been dramatic.

Batteries aside, another hurdle could be a lack of bandwidth, says Rick Hampton, wireless communications manager for Partners Healthcare System in Boston.

Nelson Fausto of the University of Washington School of Medicine has crossed this hurdle using a human fetal hepatocyte culture system that was previously developed in his lab.