Progress 3: Experimental Results
Verification of Overall Mechanisms in Solution
All of the essential mechanisms in our system were veriﬁed in solution using polyacrylamide gel electrophoresis.These mechanisms include: walker-track binding, triggering the walker, walking from one track to another, picking up cargo, walking while carrying cargo, triggering the cargo goal, dropping oﬀ cargo, and irreversibly walking from tracks to the walker goal. We are fairly confident that all of these mechanisms work as expected in solution, with a few mysteries that do not seem to interfere with the overall behavior of the system (see Gel Verification).
All of the essential mechanisms were verified using fluorescent spectroscopy. We also analyzed the kinetics of our mechanisms in solution.
Demonstration of Random Walking Robot on Origami
Random walking robot on origami was successfully demonstrated by fluorescent spectroscopy (SPEX). The results show that walking completion time dependent on the track length, and the random walking curve fits well with the theoretical equation. Goals were tagged with fluorophores whereas walkers were tagged with the corresponding quenchers. Fluorescent signals will decrease when walkers reach their goals. Unlike AFM, which studied individual origami, SPEX experiments studied the collective behavior of all the origami in solution. Hence, the SPEX results were analyzed using both Matlab simulation and mathematical formulae.
Atomic force microscopy (AFM)was used to verify the random walking mechanism on origami. We imaged individual origami rectangles (using the 1D random walking playground layout) with an inhibited, biotin/streptavidin-tagged walker at its start site, and observed that the walkers begin at their intended start site at one end of the random-walking track. We will then trigger the walker, wait for some amount of time, and image the origami again to verify that walkers have left their start site and are tending to stop at their goal at the other end of the track.