Mechanical engineers from The Ohio State University used a combination of natural and synthetic DNA in a process called DNA origami to build machines that can perform tasks repeatedly. The nano-machines were designed with full-size mechanical parts such as hinges and pistons in mind. The project is the first to prove that the same basic design principles that apply to typical full-size machine parts can also be applied to DNA - and can produce complex, controllable components for future nano-robots. The DNA origami method for making nano-structures has been widely used since 2006, and is now a standard procedure for many labs that are developing future drug delivery systems and electronics.
Project leader Carlos Castro, assistant professor of mechanical and aerospace engineering, says there are two keys to the team’s approach for designing and controlling their machines' advanced motion. The first involves making certain parts of the structure flexible (flexible parts are made from single-stranded DNA and stiffer parts from double-stranded DNA). The second key involves “tuning” the DNA structures so that the machines’ movements are reversible and repeatable. The researchers dot their structures with synthetic DNA strands that hang off the edges like the awning of a roof. Rather than join portions of the machine together permanently, these strands are designed to act like strips of hook and loop fasteners - they stick together or unstick depending on chemical cues from the machine’s surroundings.