Magnetic drive robots can achieve complex and precise operations in enclosed spaces, and their potential applications in gastroscopy and minimally invasive surgery are receiving increasing attention. Various magnetic robots have been continuously introduced. But due to the irreversible magnetization during the motion process, deformation under external magnetic fields usually can only maintain a single mode of rolling or crawling, making it difficult to adapt to complex application environments through multi-mode motion. Several studies have attempted to achieve programmable magnetization based on heating-induced remagnetization, which cannot be applied in opaque and enclosed environments. In addition, the lack of pose state detection in magnetic robots greatly limits their medical applications in non-visible environments or even inside the human body, making in-situ reprogramming and precise motion difficult. The integration of multi-mode motion and pose state detection functions on a single robot remains a challenge.

To address the in-situ motion programming and pose sensing requirements of magnetic control robots, Huawei Chen’s group from Beihang University, China reports a new carbon-magnetic multilayer thin film material prepared by 4D spray printing. The carbon layer can be electrically heated in different segments to melt the magnetic layer, which provides magnetic particle realignment under a much lower external magnetic field of ~10 mT for in situ reprogramming and multimode motions. Such a carbon layer can also precisely detect the robot’s pose (position & orientation) with its electrical resistance strain effect by creating a small deformation with ~5 mT external linear and rotating magnetic fields. Under the integration of reprogramming and sensing, necessary multimode motions, i.e. swimming, rolling, crawling, and obstacle-crossing are achieved under, and high precision poses sensing with an accuracy of ± 3 mm in position and ± 2.5º in orientation is obtained.  These combined helps realize accurate out-of-sight manipulations in the enclosed space environment, and the future potential drug delivery application in intestines and stomach are demonstrated.

Tag: Advanced Manufacturing

Source: https://spj.science.org/doi/10.34133/research.0177