In the early 1990s, research teams in a number of countries, including some at Taiwan's Industrial Technology Research Institute and a number of local universities, began similar research projects. But by 2000 there had been no breakthroughs, and many teams gave up.
1990 年初，各國研究團隊，包括台灣的工研院和各大學都投入類似的研究，但到了 2000 年仍無突破，大家紛紛放棄。