Design and Implementation of a Ferrofluid-Based Liquid Robot for Small-Scale Manipulation

Magnetic manipulation of miniature soft or liquid robots capable of deformation has gained increasing attention and is demonstrating great potential in small-scale applications, such as drug delivery, minimal invasive surgery, and manipulation of delicate objects. In this study, we introduce a liquid robot composed of ferrofluid that shows promise for small-scale magnetic manipulation applications. The objective of this work is to achieve more flexible manipulation capabilities of the robot. To this end, we utilize a redundant magnetic actuation system composed of five electromagnets and implement 4 degrees of freedom (4-DOF) control of the liquid robot in planar space. Based on the planar 4-DOF control, the liquid robot is able to perform various actions and implement versatile manipulation tasks, such as transporting objects, separating or assembling miniature parts, and operating customized tools. Furthermore, we suggest an automatic transportation method to enhance manipulation precision. A series of experiments are conducted to validate the effectiveness of the proposed method and the robot's capacity to accomplish diversified manipulation tasks. The proposed liquid robot indicates flexibility and provides novel solutions for small-scale untethered manipulation.