Magnetically Aligned Nanorods in Alginate Capsules (MANiACs): Soft Matter Tumbling Robots for Manipulation and Drug Delivery

Soft, untethered microrobots composed of biocompatible materials for completing micromanipulation and drug delivery tasks in lab-on-a-chip and medical scenarios are currently being developed. Alginate holds significant potential in medical microrobotics due to its biocompatibility, biodegradability, and drug encapsulation capabilities. Here, we describe the synthesis of MANiACs—Magnetically Aligned Nanorods in Alginate Capsules—for use as untethered microrobotic surface tumblers, demonstrating magnetically guided lateral tumbling via rotating magnetic fields. MANiAC translation is demonstrated on tissue surfaces as well as inclined slopes. These alginate microrobots are capable of manipulating objects over millimeter-scale distances. Finally, we demonstrate payload release capabilities of MANiACs during translational tumbling motion.

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Correction: Non-linear alignment dynamics in suspensions of platelets under rotating magnetic fields

Soft Matter ◽

10.1039/c9sm90079a ◽

2019 ◽

Vol 15 (17) ◽

pp. 3628-3628

Author(s):

Randall M. Erb ◽

Jana Segmehl ◽

Michalis Charilaou ◽

Jörg F. Löffler ◽

André R. Studart

Keyword(s):

Magnetic Fields ◽

Soft Matter ◽

Rotating Magnetic Fields ◽

Non Linear ◽

Linear Alignment

Correction for ‘Non-linear alignment dynamics in suspensions of platelets under rotating magnetic fields’ by Randall M. Erb et al., Soft Matter, 2012, 8, 7604–7609.

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Fast and programmable locomotion of hydrogel-metal hybrids under light and magnetic fields

Science Robotics ◽

10.1126/scirobotics.abb9822 ◽

2020 ◽

Vol 5 (49) ◽

pp. eabb9822

Author(s):

Chuang Li ◽

Garrett C. Lau ◽

Hang Yuan ◽

Aaveg Aggarwal ◽

Victor Lopez Dominguez ◽

...

Keyword(s):

Magnetic Fields ◽

Soft Matter ◽

Energy Input ◽

Aqueous Media ◽

Polymer Network ◽

Theoretical Description ◽

External Energy ◽

Rotating Magnetic Fields ◽

Inclined Surfaces ◽

Living Organisms

The design of soft matter in which internal fuels or an external energy input can generate locomotion and shape transformations observed in living organisms is a key challenge. Such materials could assist in productive functions that may range from robotics to smart management of chemical reactions and communication with cells. In this context, hydrated matter that can function in aqueous media would be of great interest. Here, we report the design of hydrogels containing a scaffold of high–aspect ratio ferromagnetic nanowires with nematic order dispersed in a polymer network that change shape in response to light and experience torques in rotating magnetic fields. The synergistic response enables fast walking motion of macroscopic objects in water on either flat or inclined surfaces and also guides delivery of cargo through rolling motion and light-driven shape changes. The theoretical description of the response to the external energy input allowed us to program specific trajectories of hydrogel objects that were verified experimentally.

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Soft Capsule Magnetic Millirobots for Region-Specific Drug Delivery in the Central Nervous System

Frontiers in Robotics and AI ◽

10.3389/frobt.2021.702566 ◽

2021 ◽

Vol 8 ◽

Author(s):

Lamar O. Mair ◽

Georges Adam ◽

Sagar Chowdhury ◽

Aaron Davis ◽

Dian R. Arifin ◽

...

Keyword(s):

Drug Delivery ◽

Central Nervous System ◽

Nervous System ◽

Targeted Delivery ◽

Ex Vivo ◽

Biological Tissues ◽

Rotating Magnetic Fields ◽

Remote Manipulation ◽

Tissue Surfaces ◽

The Central Nervous System

Small soft robotic systems are being explored for myriad applications in medicine. Specifically, magnetically actuated microrobots capable of remote manipulation hold significant potential for the targeted delivery of therapeutics and biologicals. Much of previous efforts on microrobotics have been dedicated to locomotion in aqueous environments and hard surfaces. However, our human bodies are made of dense biological tissues, requiring researchers to develop new microrobotics that can locomote atop tissue surfaces. Tumbling microrobots are a sub-category of these devices capable of walking on surfaces guided by rotating magnetic fields. Using microrobots to deliver payloads to specific regions of sensitive tissues is a primary goal of medical microrobots. Central nervous system (CNS) tissues are a prime candidate given their delicate structure and highly region-specific function. Here we demonstrate surface walking of soft alginate capsules capable of moving on top of a rat cortex and mouse spinal cord ex vivo, demonstrating multi-location small molecule delivery to up to six different locations on each type of tissue with high spatial specificity. The softness of alginate gel prevents injuries that may arise from friction with CNS tissues during millirobot locomotion. Development of this technology may be useful in clinical and preclinical applications such as drug delivery, neural stimulation, and diagnostic imaging.

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