This review focuses on magnetically driven bio-hybrid micro actuators, categorized by major biological component, for environmental and biomedical applications.

Insulator based dielectrophoresis (iDEP) is becoming increasingly important in emerging biomolecular applications, including particle purification, fractionation, and separation. Compared to conventional electrode-based dielectrophoresis (eDEP) techniques, iDEP has been demonstrated to have a higher degree of selectivity of biological samples while also being less biologically intrusive. Over the past two decades, substantial technological advances have been made, enabling iDEP to be applied from micro, to nano and molecular scales. Soft particles, including cell organelles, viruses, proteins, and nucleic acids, have been manipulated using iDEP, enabling the exploration of subnanometer biological interactions. Recent investigations using this technique have demonstrated a wide range of applications, including biomarker screening, protein folding analysis, and molecular sensing. Here, we review current state-of-art research on iDEP systems and highlight potential future work.

Using a single rotating magnetic field, RBC biohybrid micromotors can be controlled to achieve propulsion via swimming and rolling modes. The propulsion mechanism, directional control, and behavior in different fluids is investigated.

Here, we use magnetically driven self-assembled achiral swimmers made of two to four superparamagnetic micro-particles to provide insight into how swimming kinematics develop in complex, shear-thinning fluids. Two model shear-thinning polymer fluids are explored, where measurements of swimming dynamics reveal contrasting propulsion kinematics in shear-thinning fluids vs a Newtonian fluid. When comparing the velocity of achiral swimmers in polymer fluids to their dynamics in water, we observe kinematics dependent on (1) no shear-thinning, (2) shear-thinning with negligible elasticity, and (3) shear-thinning with elasticity. At the step-out frequency, the fluidic environment's viscoelastic properties allow swimmers to propel faster than their Newtonian swimming speed, although their swimming gait remains similar. Micro-particle image velocimetry is also implemented to provide insight into how shear-thinning viscosity fluids with elasticity can modify the flow fields of the self-assembled magnetic swimmers. Our findings reveal that flow asymmetry can be created for symmetric swimmers through either the confinement effect or the Weissenberg effect. For pseudo-chiral swimmers in shear-thinning fluids, only three bead swimmers show swimming enhancement, while four bead swimmers always have a decreased step-out frequency velocity compared to their dynamics in water.