Steering control of a water-running robot using an active tail

Bio‐Hybrid Cell‐Based Actuators for Microsystems

“…A wide range of microorganisms has been applied in bio‐hybrid devices. These include flagellated bacterial species, such as Escherichia coli ( E. coli ), Serratia marcescens ( S. marcescens ), Salmonella typhimurium , Vibio alginolyticus , Bacillus subtilis , strains of magnetotacic bacteria, and gliding bacterial species, such as Mycoplasma mobile . In addition to bacterial cells, strains of protozoa, such as Paramecium caudatum , Vorticella convallaria , and Tetrahymena pyriformis , and strains of algae, such as Chlamydomonas reinhardtii , have been applied in bio‐hybrid devices.…”

“…Chemoattractants cause a directed motion up a concentration gradient (i.e., toward increasing concentrations) whereas chemorepellents result in a directed motion down a concentration gradient (i.e., toward decreasing concentrations). Kim et al analyzed the chemotactic response of S. marcescens‐ driven microbeads under a linear concentration gradient of the chemoattractant, L‐threonine, and found a 64.2% improvement in speed when exposed to the chemoattractant compared to a control environment with no chemoattractant . Studies have also found an increase in the directionality of motion of S. marcescens ‐propelled microbeads when exposed to a linear concentration gradient of several types of chemoattractants, including l ‐threonine, l ‐aspartate, and Casamino acid solution .…”

“…Kim et al analyzed the chemotactic response of S. marcescens‐ driven microbeads under a linear concentration gradient of the chemoattractant, L‐threonine, and found a 64.2% improvement in speed when exposed to the chemoattractant compared to a control environment with no chemoattractant . Studies have also found an increase in the directionality of motion of S. marcescens ‐propelled microbeads when exposed to a linear concentration gradient of several types of chemoattractants, including l ‐threonine, l ‐aspartate, and Casamino acid solution . Park et al measured a 14% increase in the directional motility of S. typhimurium ‐driven microbeads within a linear chemoattractant ( l ‐aspartic acid) gradient and a 13% decrease within a linear chemorepellent (NiSO 4 ) gradient .…”

“…The performance of chemical methods for steering control also lacks behind other control methods. Although directional motion has been observed using chemical gradients, a large degree of stochasticity still exists in the system; therefore, at any given point in time, the bio‐hybrid device may not be moving in the desired direction . Over the course of tens of seconds, however, the net motion of the bio‐hybrid device will be directional (see Section for a demonstrated example).…”

Active Tail Configurations for Enhanced Body Reorientation Performance

“…It has already been shown that controlling the orientation at the initiation of gliding has a significant effect on the gliding performance. [ 11 ] Previous work has already shown the benefits of an active tail in animals including, Libby et al, [ 12 ] Chang‐Siu et al, [ 13 ] and Jusufi et al, [ 14 ] who observed how lizards use their active tails for body orientation control. This concept was then incorporated into a robot, which showed similar behaviors.…”