The advancement of flexible technology, such as wearable devices, foldable mobile, and automobiles, has entered a new era. Recently, MICAtronics using flexible muscovite carriers has been introduced as a novel area for flexible technology. The muscovite substrate addresses challenges such as thermal budget and chemical stability, offering outstanding environmental stability and an alternative approach to the prevalent polymer-based soft technology. However, the role of muscovite in these studies has been limited to serving as substrates. We expand the scope of muscovite applications by proposing a new form called “intercalated muscovite.” In this study, we insert transition metal ions, creating a novel layout of muscovite substrates. Subsequent heat treatment and controlled atmospheres can generate various forms of inserted species. These intercalated systems reveal new physical properties of muscovite substrates, offering a fresh avenue for MICAtronics.