Proofreading mechanism for robust self-assembly

Designing components that can robustly self-assemble into complex structures is a grand challenge. Biological examples show that complex assemblies are possible, surmounting kinetic traps in the free energy landscape, as well as thermal noise. A principled way to improve assembly beyond equilibrium yield is to use proofreading, in which energy is consumed to increase the yield of the desired structures. Here we introduce an explicit proofreading scheme for the assembly of colloidal structures. We consider a patchy particle system and demonstrate that a two staged proofreading mechanism can substantially improve assembly yield and robustness. In the first stage, we learn local rules whereby particles consume energy to increase their binding strengths when they detect a local environment corresponding to the desired structure. The second stage corrects potential errors during the assembly process by adding a reverse pathway to decrease the bond strengths via an intermediate state. The scheme shows significant yield improvements in the regime where structures typically are kinetically trapped. We demonstrate that not only does the scheme increase assembly yield of structures with perfectly designed components, with a much broader temperature range where the desired yield is high, it also exhibits superior robustness against intrinsic quenched disorder. Our findings illuminate a pathway for advancing the programmable design of synthetic living materials, potentially fostering the synthesis of novel biological materials and functional behaviors.