Ingestible Functional Magnetic Robot with Localized Flexibility (MR‐LF)

Abstract

The gastrointestinal (GI) tract plays a crucial role in the human body as a naturally evolved interface between the body and its environment. Ingestible electronics perform surgical-free screenings and diagnoses within the GI tract and have been proposed since 1957. [1][2][3][4] Recent advancements have demonstrated the ability to integrate ingestible electronics with sensing, actuation, and drug delivery capabilities, with several examples that have been FDA approved and are in clinical use. [5][6][7][8] For example, the pill-shaped PillCam provides access to areas of the GI tract that are challenging or infeasible via endoscopic procedures. [8] However, the size of an ingestible device is fundamentally constrained to enable swallowing (e.g., PillCam SB 3 has a diameter of 11.4 mm and a length of 26.2 mm) [9] and to mitigate the risks of unexpected retention (1.4% for conventional capsule endoscopes) [10] or intestinal obstruction that requires surgical interventions. The limitation in size constrains the possible functionalities that can be integrated into an ingestible system, especially since active components such as microelectronics are rigid and planar parts that have to be assembled into the system. For example, most ingestible electronics do not have the ability to be actively transported toward target regions of interest. [8] Indeed, integrating functionalities into ingestible, untethered robots with active locomotion capabilities can enable a broader range of surgical-free diagnostic and treatment strategies. [11][12][13][14][15] Earlier research has demonstrated a wide range of locomotion strategies for small-scale robots, including legged, [16,17] rolling, [18][19][20][21] peristaltic (i.e., earthworm-like), [22][23][24][25][26][27][28] undulatory, [29][30][31] crawling, [32][33][34][35][36][37][38][39][40][41][42][43] and other motions. [6,[44][45][46][47][48][49][50][51][52] Among the demonstrated mechanisms, magnetically controlled actuation is particularly promising because it does not require onboard power or control systems, [45] freeing critically needed space for additional functional integration.Recent advances have demonstrated the ability of miniature magnetic crawlers to actively transport cargo in complex and confined systems, such as the GI tract, by leveraging magnetic fields to induce locomotion. For instance, Zhao et al. demonstrated a magnetic origami robot that crawled by in-plane contraction [22] where the anisotropic friction on the robot's feet enabled forward locomotion that can be steered. Nevertheless, the need for anisotropic friction on the feet also precluded bidirectional locomotion in a confined space, such as in a lumen, where reversing direction by turning in place is challenging. Other recent works demonstrated entirely-soft crawlers with impressive multi-gait bending locomotion that could transport objects by gripping and direct attachment, [53][54][55] including cargos 20 times their mass

Functional capsule robots: a review of locomotion, pose, medical operation and wireless power transmission reported in 2018–2023

“…However, how to remotely control the collection and dispersion of each functional module is the focus of research. A design of centralized compartment in magnetic robot by imparting localized flexibility was demonstrated, that enables capsule robot to be readily integrated with functional modular, such as commercial electronics and medication [76]. Furthermore, adaptive magnetic levitation is an ideal way for capsule robots to move.…”

Magnetic-Controlled Microrobot: Real-Time Detection and Tracking through Deep Learning Approaches

“…In recent years, microrobots have shown great advantages in the field of biomedical applications. With the development of microrobots, various aspects such as their driving methods [ 2 , 3 , 4 , 5 , 6 ], recognition and tracking [ 7 , 8 ], biosafety [ 9 ], targeted drug delivery methods [ 10 , 11 , 12 ], and multi-functional integration [ 13 , 14 ] have attracted widespread attention. For example, a magnetically driven rotary ablation catheter robot [ 15 ] was employed to remove calcified deposits from arterial stenosis and occlusion.…”

Dynamic Tuning of Plasmonic Hot‐Spot Generation through Cilia‐Inspired Magnetic Actuators

“…[32,33] Among various methods, applying an external magnetic field to create a torque or force on the soft actuator is one of the simplest yet effective actuation approaches. [34][35][36][37][38][39][40][41][42][43][44] More importantly, this actuation method is transparent and noninvasive, and high temporal resolution is possible by controlling the amplitude, gradient, and direction of the magnetic field. Although some interesting studies on sample capturing and trapping have been reported using soft actuator platforms, [45][46][47] their use in hot-spot engineering is still very limited.…”