Any boundary would not enclose the space beyond and, thus, would not be the entire universe. The smallest mechanism of existence is a ring of primary motion, massless motion cycling at the speed of C, the speed of light. It can be neither generated nor destroyed. Movement is the fundamental nature of existence. Time is a human concept and is very useful to us at the macro scale, but has nothing to do with the activity of existence at the primary particle level.
Structure is provided by stable patterns of cycling motion.
Energy is provided by the translation of primary motion among the particles. All activity in the universe translates from primary motion at the primary particle level. Charge, or valence, is a function of cycling primary motion within the electron, with respect to patterns within the nucleus of an atom. All bonding activity in terms of valence is a function of nuclear ring differential and the activity of the electron. There are three families of primary particles, four if you want to give a gamma particle its own category.