Imagine the last time something in your house broke -- a cup or plate, a bracket, a door handle, a component in an electrical appliance or mechanical device, a hinge, a switch. The list can go on and on. But instead of tossing the entire device out, or heading to the local hardware or electrical store to find an often costly replacement, imagine if you could recreate that object or component in your home on a 3D printer. Now imagine if the 3D printer you use to make that part could recreate itself as well.

This idea of self-replication has been around for some time, but until recently such technology has been far from the reach of the average person, costing tens of thousands of dollars to setup.

But researchers at the University of Bath in the UK gained worldwide attention in 2005 with the RepRap project -- an open source self-copying, rapid-prototyping machine that can manufacture mechanical parts and even reproduce itself at a fraction of the cost.

RepRap is short for Replicating Rapid-prototyper -- a self-replicating machine often described as a 3D printer that can manufacture components by building them up in layers of plastic. This technique is known as Fused Deposition Modelling Rapid Prototyping.

Software development for RepRap was done using Linux, and all of the project's software and hardware components fall under the GNU General Public License, meaning the design specifications are free for all to use and improve upon, with only several hundred dollars required for materials.

The design for the first version of RepRap, known as Darwin 1.0, has not yet been finalised. But it is close enough that kits are available for sale and early adopters have already began building their own, safe in the knowledge that when the time comes to upgrade, the RepRap can make its own parts.

Currently, Darwin 1.0 can manufacture about 65 per cent of itself, excluding electrical circuitry, motors, nuts and bolts. The next version of RepRap - Mendel 2.0, will boast an electrical conductor allowing the machine to make its own and other circuitry, bringing it one step closer to complete self-replication.

Video demonstrations of the RepRap in action can be viewed here, along with items the RepRap can produce.

Within the next five years the RepRap team envisage that it will be possible to manufacture 90 per cent of a mobile phone or MP3 player on the RepRap.

Computerworld recently spoke to Dr Adrian Bowyer, founder and head of the RepRap project at the University of Bath. Dr Bowyer talks about RepRap's capabilities, its history, why its hardware and software components are open source, and where self-replicating technology and the RepRap are heading in the near future.