This work, by Bhalla et al., is very useful for the design of nanoscale and microscale structures and DNA computing using self-assembly. It is also effective for the creation of more complex physical self-assembling systems.

The authors very elegantly handle the problem of self-assembly and propose their approach to it in a very specific manner. They review the background material and provide a new theoretical model for self-assembly, which includes a set of self-assembly rules. They analyze and compare the non-staged versus the staged assembly process to establish the novelty of their work.

They conduct four experiments that demonstrate the creation of self-assembled structures from a set of components that are divided into two time intervals according to the physical features. Components are fabricated and placed in orbital shaking environments, which are used to demonstrate the role of morphological information in spatial component movement, in two and three dimensions. The entire treatment of staged self-assembly is perfectly balanced between theory and practice. The theoretical development is technically very sound and the experimental results are very convincing. Finally, the authors cover a good list of references in connection to their work.

Above all, the work definitely adds a new dimension to the architecture of life.