This is known as a charge pump, and is the third concept described in the linked article. The article only mention one flying capacitor, but you can use more th

This is known as a charge pump, and is the third concept described in the linked article. The article only mention one flying capacitor, but you can use more than one and connect them in series to get a higher multiple of the input voltage. Ben Eater also did a nice introduction to charge pumps by building a simple one on a breadboard: https://www.youtube.com/watch?v=4alV5LzHLE4&t=704s https://www.youtube.com/watch?v=4alV5LzHLE4&t=704s