Reconfigurable artificial microswimmers with internal feedback

Alvarez, Laura; Fernández-Rodríguez, Miguel Ángel; Alegría, Ángel; Arrese-Igor, Silvia; Zhao, Kai; Kröger, Martin; Isa, Lucio

doi:10.1038/s41467-021-25108-2

Cited by 51 publications

(49 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[ 117 ] This strategy has been experimentally realized using geometrically and compositionally asymmetric colloids containing polystyrene particles and thermoresponsive microgels. [ 118 ]…”

Section: Harnessing Fluid–structure Interactionsmentioning

confidence: 99%

On‐Board Mechanical Control Systems for Untethered Microrobots

Dolev

Kaynak

Sakar

2021

Advanced Intelligent Systems

View full text Add to dashboard Cite

An autonomous robot perceives its environment, makes decisions based on acquired information and programmed routines, and then actuates a movement or performs a manipulation task within that environment. The idea of microrobotics is primarily based on teleoperated mobile micromachines equipped with manipulation capabilities such as actuated grippers and drug‐loaded reservoirs. Due to miniaturization challenges, the majority of these micromachines are wirelessly actuated using magnetic fields or acoustic waves. A step toward complete autonomy is the development of on‐board control systems that directly transduce environmental stimuli such as heat and pressure into actuation, without going through the perception and computation cycles. Following the analogy of the central nervous system for the architecture of conventional autonomous robots, the next‐generation microrobots are expected to possess reflexes that would allow them to autonomously navigate inside structured microenvironments and perform targeted and triggered operations. Herein, the construction of on‐board control systems using stimuli–responsive materials, nonlinear mechanical mechanisms, and fluid–structure interactions is described. Recent advances in macroscale soft robotics and mechanical metamaterials are highlighted with the hope that they inspire solutions for microrobotics.

show abstract

“…[ 117 ] This strategy has been experimentally realized using geometrically and compositionally asymmetric colloids containing polystyrene particles and thermoresponsive microgels. [ 118 ]…”

Section: Harnessing Fluid–structure Interactionsmentioning

confidence: 99%

On‐Board Mechanical Control Systems for Untethered Microrobots

Dolev

Kaynak

Sakar

2021

Advanced Intelligent Systems

View full text Add to dashboard Cite

show abstract

“…We hypothesized that by introducing anisotropy to the internal droplet morphology and composition, an asymmetry in the fluid flows surrounding a droplet and thus a controllable selective and dynamically tunable directionality in the locomotion of emulsion droplets can be achieved. Whereas solid Janus colloids with two different chemistries on each side of the particle have found widespread application in the design of active microswimmers with directional propulsion profiles 47 , a permanently asymmetric, dynamic, and fluid-based system such as spherical biphasic Janus droplets has not been explored previously in this context. Our Janus emulsion droplets are comprised of two phase-separated oils that align with gravity, dispersed within an aqueous continuous phase.…”

Section: Introductionmentioning

confidence: 99%

Reversible morphology-resolved chemotactic actuation and motion of Janus emulsion droplets

2022

View full text Add to dashboard Cite

We report, for the first time, a chemotactic motion of emulsion droplets that can be controllably and reversibly altered. Our approach is based on using biphasic Janus emulsion droplets, where each phase responds differently to chemically induced interfacial tension gradients. By permanently breaking the symmetry of the droplets’ geometry and composition, externally evoked gradients in surfactant concentration or effectiveness induce anisotropic Marangoni-type fluid flows adjacent to each of the two different exposed interfaces. Regulation of the competitive fluid convections then enables a controllable alteration of the speed and the direction of the droplets’ chemotactic motion. Our findings provide insight into how compositional anisotropy can affect the chemotactic behavior of purely liquid-based microswimmers. This has implications for the design of smart and adaptive soft microrobots that can autonomously regulate their response to changes in their chemical environment by chemotactically moving towards or away from a certain target, such as a bacterium.

show abstract

“…In this work, we fulfill these requirements by fabricating artificial microswimmers constituted by colloidal clusters or "molecules" [15,16,17], which combine responsive and non-responsive particles [18]. The clusters are deterministicly prepared by means of sequential capillarity-assisted particle assembly (or sCAPA) [19].…”

Section: Introductionmentioning

confidence: 99%

Self-propelling colloidal finite state machines

van Kesteren,

Alvarez,

Arrese-Igor

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Endowing materials with physical intelligence holds the key for a progress leap in robotic systems. In spite of the growing success for macroscopic devices, transferring these concepts to the microscale presents several challenges connected to the lack of suitable fabrication and design techniques, and of internal response schemes that connect the materials' properties to the function of an autonomous unit. Here, we realize self-propelling colloidal clusters which behave as simple finite state machines, i.e. systems built to possess a finite number of internal states connected by reversible transitions and associated to distinct functions. We produce these units via capillary assembly combining hard polystyrene colloids with two different types of thermo-responsive microgels. The clusters, actuated by spatially uniform AC electric fields, adapt their shape and dielectric properties, and consequently their propulsion, via reversible temperature-induced transitions controlled by light. The different transition temperatures for the two microgels enable three distinct dynamical states corresponding to three illumination intensity levels. The sequential reconfiguration of the microgels affects the velocity and shape of the active trajectories according to a pathway defined by tailoring the clusters' geometry during assembly. The demonstration of these simple systems indicates an exciting route to build more complex units with broader reconfiguration schemes and multiple responses towards the realization of autonomous systems with physical intelligence at the colloidal scale.

show abstract

Reconfigurable artificial microswimmers with internal feedback

Cited by 51 publications

References 49 publications

On‐Board Mechanical Control Systems for Untethered Microrobots

On‐Board Mechanical Control Systems for Untethered Microrobots

Reversible morphology-resolved chemotactic actuation and motion of Janus emulsion droplets

Self-propelling colloidal finite state machines

Contact Info

Product

Resources

About