Soft micromachines with programmable motility and morphology

Huang, Hen-Wei; Sakar, Mahmut Selman; Petruska, Andrew J.; Pané, Salvador; Nelson, Bradley J.

doi:10.1038/ncomms12263

Cited by 538 publications

(499 citation statements)

References 35 publications

Supporting

Mentioning

494

Contrasting

Unclassified

Order By: Relevance

“…hape-programmable matter refers to active materials that can be controlled by heat (1)(2)(3)(4)(5), light (6,7), chemicals (8)(9)(10)(11)(12)(13), pressure (14,15), electric fields (16,17), or magnetic fields (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33) to generate desired folding or bending. As these materials can reshape their geometries to achieve desired time-varying shapes, they have the potential to create mechanical functionalities beyond those of traditional machines (1,15).…”

mentioning

confidence: 99%

Shape-programmable magnetic soft matter

Lum

Zhou

Dong

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

474

473

View full text Add to dashboard Cite

Shape-programmable matter is a class of active materials whose geometry can be controlled to potentially achieve mechanical functionalities beyond those of traditional machines. Among these materials, magnetically actuated matter is particularly promising for achieving complex time-varying shapes at small scale (overall dimensions smaller than 1 cm). However, previous work can only program these materials for limited applications, as they rely solely on human intuition to approximate the required magnetization profile and actuating magnetic fields for their materials. Here, we propose a universal programming methodology that can automatically generate the required magnetization profile and actuating fields for soft matter to achieve new time-varying shapes. The universality of the proposed method can therefore inspire a vast number of miniature soft devices that are critical in robotics, smart engineering surfaces and materials, and biomedical devices. Our proposed method includes theoretical formulations, computational strategies, and fabrication procedures for programming magnetic soft matter. The presented theory and computational method are universal for programming 2D or 3D time-varying shapes, whereas the fabrication technique is generic only for creating planar beams. Based on the proposed programming method, we created a jellyfish-like robot, a spermatozoid-like undulating swimmer, and an artificial cilium that could mimic the complex beating patterns of its biological counterpart.programmable matter | multifunctional materials | soft robots | magnetic actuation | miniature devices S hape-programmable matter refers to active materials that can be controlled by heat (1-5), light (6, 7), chemicals (8-13), pressure (14, 15), electric fields (16, 17), or magnetic fields (18-33) to generate desired folding or bending. As these materials can reshape their geometries to achieve desired time-varying shapes, they have the potential to create mechanical functionalities beyond those of traditional machines (1, 15). The functionalities of shape-programmable materials are especially appealing for miniature devices whose overall dimensions are smaller than 1 cm as these materials could significantly augment their locomotion and manipulation capabilities. The development of highly functional miniature devices is enticing because, despite having only simple rigid-body motions (34-36) and gripping capabilities (37), existing miniature devices have already been used across a wide range of applications pertaining to microfluidics (38, 39), microfactories (40, 41), bioengineering (42, 43), and health care (35, 44).Among shape-programmable matter, the magnetically actuated materials are particularly promising for creating complex timevarying shapes at small scales because their control inputs, in the form of magnetic fields, can be specified not only in magnitude but also in their direction and spatial gradients. Furthermore, as they can be fabricated with a continuum magnetization profile, m, along their bodies, these magne...

show abstract

mentioning

confidence: 99%

Shape-programmable magnetic soft matter

Lum

Zhou

Dong

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

474

473

View full text Add to dashboard Cite

show abstract

“…Very recently, motility of peritrichously flagellated microorganisms has also been mimicked using a magnetically actuated multilink nanoswimmer 16. Huang et al17, 18 have also integrated self‐folded hydrogel tubes to artificially approximated bacterial flagella to enhance the overall motility of the soft microrobot. Lum et al have proposed a universal programming methodology to achieve desired magnetization profiles for soft materials and enable realization of time‐varying shapes 19.…”

Section: Introductionmentioning

confidence: 99%

Swimming Back and Forth Using Planar Flagellar Propulsion at Low Reynolds Numbers

et al. 2017

View full text Add to dashboard Cite

Peritrichously flagellated Escherichia coli swim back and forth by wrapping their flagella together in a helical bundle. However, other monotrichous bacteria cannot swim back and forth with a single flagellum and planar wave propagation. Quantifying this observation, a magnetically driven soft two‐tailed microrobot capable of reversing its swimming direction without making a U‐turn trajectory or actively modifying the direction of wave propagation is designed and developed. The microrobot contains magnetic microparticles within the polymer matrix of its head and consists of two collinear, unequal, and opposite ultrathin tails. It is driven and steered using a uniform magnetic field along the direction of motion with a sinusoidally varying orthogonal component. Distinct reversal frequencies that enable selective and independent excitation of the first or the second tail of the microrobot based on their tail length ratio are found. While the first tail provides a propulsive force below one of the reversal frequencies, the second is almost passive, and the net propulsive force achieves flagellated motion along one direction. On the other hand, the second tail achieves flagellated propulsion along the opposite direction above the reversal frequency.

show abstract

“…The diameter of the particles was 200-300 nm and their length was 1-2 µm, and they achieved swimming speeds in water of an order of 25 µm.s -1 . Very recently Huang et al [30] developed ABF particles where the particle shape can be reconfigured.…”

Section: Self-propelled Artificial Bacterial Flagella (Abf) Particlesmentioning

confidence: 99%

Self-propelled nanofluids a path to a highly effective coolant

Hasadi

Crapper

2017

Applied Thermal Engineering

View full text Add to dashboard Cite

We propose a new self-propelled nanofluid having advantageous thermal and rheological properties at the same time. The nanofluid consists of a low volume fraction of self-propelled particles known as Artificial Bacterial Flagella (ABF), which will swim as pushers in a manner similar to the swimming of E-coil microorganisms with flagella. A theoretical model is introduced, describing the mechanisms responsible for the reduction of viscosity. The model shows that the swimming velocity of the particle and its geometry play an essential role in the reduction of the suspension viscosity. The results obtained from the theoretical model compare qualitatively with experiments in the literature. The model shows a significant decrease in viscosity at very low volume fractions, and that the viscosity of the suspension is reduced as the volume fraction of the particles increases. Using an in-house finite volume code, we numerically simulate natural convection effects in our ABF self-propelled nanofuid inside a square cavity heated from its vertical sides. Simulations are conducted at volume fractions of 0.7%, 0.8% and 0.83%, comparing the performance of a self-propelled nanofluid with conventional non-active nanofluids (i.e. carbon nanotubes in water). The results show that the heat transfer rate measured by the Nusselt number is three times higher than for the case of classical nanofluids and pure water at the same operating conditions and 0.83% volume fraction of particles. Also, due to the very dilute volume fractions of particles in the proposed nanofluid, their stability can endure for long operating times. There is also a significant decrease in the viscosity (around 25 times lower than water) which will result in a significant reduction in the pumping power.2

show abstract

Soft micromachines with programmable motility and morphology

Cited by 538 publications

References 35 publications

Shape-programmable magnetic soft matter

Shape-programmable magnetic soft matter

Swimming Back and Forth Using Planar Flagellar Propulsion at Low Reynolds Numbers

Self-propelled nanofluids a path to a highly effective coolant

Contact Info

Product

Resources

About