Tsukuba city is one of the biggest science city in the world. There are a lot of science institutes where you can visit to watch and touch real science. It takes 45mins from Tokyo Akihabara by Tsukuba Express. For more info please check the URL below.
https://www.i-step.org/tour/english.html
(Tsukuba science tour office HP)
科学の街・つくば で施設見学！各施設を廻る路線バス ”つくばサイエンスツアーバス”を使うと、簡単に見学できます。詳細はつくばサイエンスツアーオフィスHPから！
https://www.i-step.org/tour/index.html