Teruo Fujii of the University of Tokyo in Japan and his colleagues hope that they will eventually create a fully automated artificial uterus in which egg and sperm are fed in at one end and an early embryo comes out the other, ready for implanting in a real mother.
The researchers believe that such a device can improve the success rate of in vitro fertilisation (IVF).
"While there have been many advances in the production of in vitro embryos, these embryos are still sub-optimal [compared] to their in vivo counterparts," says Matt Wheeler of the University of Illinois in Urbana-Champaign who is also working on automated IVF systems.
He says that one of the reasons for this is that during IVF, eggs or embryos are often moved or washed with culture fluid, causing changes in temperature and pH.
With a view to tackling these problems, Fuji and his colleagues created a "lab on a chip", two millimetres across and 0.5 millimetres high, in which up to 20 eggs can be fertilised and then grown until they are ready for implantation.
Endometrial cells, which line real wombs, are also grown in the device, so that the chemicals they produce can reach the embryos and help them grow.
"We are providing the embryos with a much more comfortable environment, mimicking what happens in the body," Fujii says.
Experiments on mice suggest that the chip is more successful than traditional IVF at producing embryos that will grow into healthy foetuses. The researchers found that 44 per cent of embryos developed into healthy foetuses upon implantation into mice, as compared to 40 per cent of those grown through "microdrop" IVF.
"It's not just about more embryos surviving to be implanted, they also seem to be doing better once they are implanted," says Wheeler.
Having obtained approval from the authorities, Fuji's team is expected to begin testing the device on human embryos later this year. Wheeler's team has already automated them, and he feels that combining his approach with that of Fuji may produce even better results.
He says that the chip may also be used for growing genetically modified animals, stem cells and cloned embryos.