A research team in Japan said Friday that it has succeeded in replicating contraction and stretching in a small muscle grown from rat cells, local media reported Friday.

The development, to be detailed at an international conference in the United States starting Sunday, is expected to prove useful in the field of regenerative medicine, Kyodo reported Friday.

"It could also lead to the development of robots able to move naturally using muscles," said the team leader Shoji Takeuchi, a professor at the University of Tokyo.

By placing rat muscle cells on jelly-like sheets, the team was able to cultivate artificial muscle tissues 8 millimeters long and 1.5 millimeters thick.

The team attached two muscle tissues to either side of a 2- centimeter-long artificial joint and was able to contract and stretch them smoothly by applying an electric stimulus.

The muscles previously shrank and stiffened around two hours after being used to move an artificial joint. The team was able to extend the period to two days, though it notes that the muscles get "tired" when stimulated repeatedly and their performance deteriorates.