Recent work has demonstrated the viability of DNA robotics
and artificial molecular machines for molecular transportation
and cargo sorting with potential applications in manufacturing
responsive molecular devices, programmable therapeutics,
and autonomous chemical synthesis. We extend
previous work on cooperative molecular transportation using
artificial molecular machines, where we similarly functionalize
DNA-conjugated microtubules driven by kinesin motor
proteins. DNA-functionalized microtubules propelled by
surface-adhered kinesin motors enable the self-organization
of molecular swarms, where such swarms load and transport
cargo (microbead) in a simulated chemical environment. We
demonstrate programmable molecular swarms for cargo sorting
and cooperative transport. Cargo loading occurs when
sufficient microtubules are at the same location as the cargo,
and cargo unloading occurs at specific points in the environment
through interaction with localized DNA species. Our
contribution is the design of a chemotaxis molecular controller,
forcing the swarm to tumble (random change direction)
when the system is not following a molecular gradient
corresponding to the cargo type, thus directing it to specific
points for cargo unloading. This work thus contributes to the
open problem of how to best design programmable molecular
machines for various tasks in microscopic environments
