Metal-Organic Frameworks Based Nano/Micro/Millimeter-Sized Self-Propelled Autonomous Machines.

Synthetic nano/micro/millimeter-sized machines that harvest energy from the surrounding environment and then convert it to motion have had a significant impact on many research areas such as biology (sensing, imaging, and therapy) and environmental applications. Autonomous motion is a key element of these devices. A high surface area is preferable as it leads to increased propellant or cargo-loading capability. Integrating highly ordered and porous metal-organic frameworks (MOFs) with self-propelled machines is demonstrated to have a significant impact on the field of nano/micro/millimeter-sized devices for a wide range of applications. MOFs have shown great potential in many research fields due to their tailorable pore size. These fields include energy storage and conversion; catalysis, biomedical application (e.g., drug delivery, imaging, and cancer therapy), and environmental remediation. The marriage of motors and MOFs may provide opportunities for many new applications for synthetic nano/micro/millimeter-sized machines. Herein, MOF-based micro- and nanomachines are reviewed with a focus on the specific properties of MOFs.