Fig. 1.

The microfluidic devices used in this study. (a) [scale bar = 1.5 mm] Snapshot of the fabricated HSRT drug screening device comprising two microchannels tapering into a drug well. For illustration purpose, the two chemically separated agarose mixtures are colored with yellow and blue dyes. The soft-lithography mask is shown to illustrate the parallelism of the design. A 3D model showing the main components of the microfluidic design is also shown for further clarity. (b) [scale bar = 750 μm] Snapshot of the fabricated T-shaped microfluidic device showing the three electrode ports and sample electric fields at the respective ports. Worms are inserted in the left port and their preference to move towards either cathode is tracked with the imaging unit. (c) [scale bar = 300 μm] Time-lapsed images of a LEVR O. dentatum nematode in the straight microchannel. The position of the worm’s head is indicated by an arrow. Initially, a 5 V cm⁻¹ electric field directed to the right side is applied for a period of 6 s. The worm moves along the direction of the electric field. Thereafter, the direction of the electric field is reversed. The worm turns its body around at the 12th second and continues in the new direction of the electric field.