Core Concepts
The author presents a magnetic millirobot capable of walking on slippery biological surfaces to deliver cargo efficiently. The core reasoning lies in the development of a versatile and effective miniaturized vehicle for targeted cargo delivery.
Abstract
The content introduces a magnetic millirobot designed for targeted cargo delivery on challenging biological surfaces. The robot's locomotion, actuation system, and cargo deployment capabilities are thoroughly discussed and experimentally validated. Key aspects include the design, fabrication, control mechanisms, and potential biomedical applications of the millirobot.
The magnetic millirobot is equipped with sharp metallic tips as feet to anchor itself on slippery biological tissues efficiently. It can walk by alternating rotations around its front feet, exhibiting a bipedal gait. The robot's motion sequences enable it to climb vertical walls and carry loads up to four times its weight.
A permanent magnet set-up allows wireless actuation of the millirobot within human-scale volumes, providing precise control for complex trajectories and cargo delivery. The robot can inject liquid drugs into tissues at target locations after reaching them successfully.
Experimental results validate the effectiveness of the millirobot's locomotion on hydrogel phantoms and ex vivo animal tissues. Characterization studies demonstrate how varying parameters such as oscillating angle, pitch angle, frequency, and cargo weight affect the robot's speed and stability during movement.
The study highlights the potential of the magnetic actuation system for powering small-scale robots in biomedical applications like drug delivery and minimally-invasive procedures. Future research aims to optimize magnetic fields for specific applications and enhance biocompatibility aspects for real medical scenarios.
Stats
The working volume achieved by the magnetic actuation system is 35 x 40 x 35 mm3.
The robot can carry loads up to ~100 mg, approximately four times its body weight.
A pitch angle increase from 39˚ to 66˚ linearly increases the robot's speed from 0.3 to 2.0 mm/s.
An oscillating frequency of 1.2 Hz ensures stable walking motion of the millirobot.
The gradient force generated by magnets allows crawling at speeds up to 0.9 mm/s against gravity.
Quotes
"The robust gait of our millirobot on rough biological terrains combined with its heavy load capacity make it a versatile and effective miniaturized vehicle."
"Our deployment mechanism allows injection directly into soft tissues which will be beneficial for many medical applications."