What Triggers the Dynamic Self-Assembly of Molecules and Materials?

Dynamic self-assembly has emerged as one of the reliable approaches to create complex materials with more life-like functions. In a typical dynamic self-assembly process, the external triggers activate the building blocks to initiate the assembly step to form transiently stable higher-order structures. These external triggers provide a constant supply of energy to maintain the transiently stable self-assembled states. The withdrawal or consumption of the trigger deactivates the building block in the aggregates, thereby initiating the disassembly step. A precise control over the interplay between the deterministic and nondeterministic forces is the key to achieving a dynamic self-assembly process. This demands the appropriate choice of building blocks as well as triggers, which has led to the development of a wide range of triggers in dynamic self-assembly. Through this Perspective, we intend to highlight the functional diversities, prospects, and challenges associated with different classes of "triggers" by bringing them under one platform. Such treatment will help us to identify the missing features and deduce a guideline for the development of ideal triggers. A few of the desirable features that a trigger should possess, along with probable ways to achieve them, are discussed, as well. In summary, the Perspective covers many intriguing aspects of triggers that can be helpful for researchers to achieve precise spatiotemporal control over various interparticle interactions, which is essential to obtaining the desired outcome from a dynamic self-assembly process.