University of California at Riverside researchers used the tip of a scanning tunneling microscope (STM) as a nanoscale actuator to individually guide molecules one at a time and step-by-step through a chemical reaction.

Their technique fine-tunes the reactivity of groups of molecules, offering a way to optimize atomic-scale construction of complex molecules on surfaces.

In 2000, researchers found that the STM could assemble individual biphenyl molecules from elementary building blocks. But because they lacked precise control, little progress had been made toward the assembly of larger and more useful molecules.

University of California at Riverside news release