Rising costs of materials and manufacturing,[citation needed] as well as public interest in more environmentally friendly electronics materials, have supported development of organic based electronics in more recent years. In 1986, Mitsubishi Electric researchers H. Koezuka, A. Tsumura and Tsuneya Ando reported the first organic field-effect transistor,[13][14] based on a polymer of thiophene molecules.[15] The thiophene polymer is a type of conjugated polymer that is able to conduct charge, eliminating the need to use expensive metal oxide semiconductors. Additionally, other conjugated polymers have been shown to have semiconducting properties.