Magnetic Milligripper Platform for Biomedical and Biological Applications.

Achieving precise, untethered manipulation at the millimeter scale remains a fundamental challenge in minimally invasive medicine. Magnetic milligrippers have emerged as promising untethered tools for grasping, transporting, and releasing objects in confined anatomical environments, yet most existing rigid designs rely on multi-component assemblies with dedicated hinges or joints that require complex fabrication processes. Here, we present a simple, cost-effective rigid magnetic milligripper based on a folded titanium structure with two inclined permanent magnets. Actuated by a three-axis Helmholtz-Maxwell coil system, it enables orientation and translation control, as well as reversible opening. The actuation platform is coupled to a joystick-based control interface, allowing intuitive, real-time steering and opening of the milligripper by a single operator. The design is established with an analytical magnetic dipole model and validated through both finite-element simulations and experimental characterization, which together confirm reproducible, fully elastic operation across the investigated actuation range. The strong agreement between analytical, numerical, and experimental results establishes this architecture as a mechanically robust and scalable proof-of-concept platform for magnetic micromanipulation, with direct relevance to future minimally invasive biomedical applications.