Credit: Image courtesy of Argonne National Laboratory
In a “living” liquid crystal, particles swim along defined lanes. A new predictive computational model suggests a way to trap bacteria or any other active particles within specific areas. Left: Bacteria accumulate (yellow area) behind the core of a T-shaped “+1/2 defect” and deplete (blue) for the Y-shaped “−1/2 defect”. The white arrow indicates the direction of motion of the defect. Center: Experiments confirmed these predictions. The green lines depict the orientation of liquid crystal molecules that act as guides for swimming bacteria (red). Right: A close-up of the area within the blue box demonstrates the validity of the simulation. White lines depict orientations of the T-shaped (red) and Y-shaped (green) defects. The white scale bars represent 50 micrometers.