Thermoelectric power battery using al2o3 nanochannels of 10 nm diameter for energy harvesting of low-grade waste heat by Van Toan, Nguyen, Hasnan, Megat Muhammad Ikhsan Megat, Udagawa, Daiki, Inomata, Naoki, Toda, Masaya, Said, Suhana Mohd, Sabri, Mohd Faizul Mohd, Ono, Takahito