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A new, more precise system for creating miniature medical micro-tools that may someday be used in minimally invasive surgery.

To help meet the growing demand for miniature tools like micro-catheters and micro-tweezers, scientists at led by Professor Guang-Zhong Yang have devised a new, more precise system for creating micro-tools that may be used in minimally invasive surgery. Their most recent paper on “” is published in the latest issue of  this week.

Their simple approach uses a pair of magnetic micro-robots that can grasp and release 2D sheets of micro-electronic circuitry and orient them onto complex 3D fibres – addressing a lack of precision that has previously hindered attempts to build fibre-based robotic tools. While the use of flexible fibres equips micro-tools with the ability to image, sense and handle tiny objects, these tools require other tiny parts like sensors or micro-grippers to function fully, and such additions remain a challenge to implement at a microscopic scale.

To this end, the team developed two 2 millimetre–by–3 millimetre, 200-micrometer-thick micro-robots to align floating electronic circuits on a fibre during a wet transfer process. The position and orientation of the micro-robots were controlled at the air/water interface by a permanent magnet. The stiffness of the position controlled was 0.2 newton millimetre, leading to an average force of 0.5 newton. The non-homogeneous magnetic field of the magnet, associated with different preferred magnetisation directions recorded in the micro-robots, allowed the distance between the two micro-robots to be precisely controlled. This extra degree of freedom was used to control the micro-robot pair as a tweezer to grab and release floating electronic patterns, whereas the others were used to align the pattern position and orientation with the fibre.   

The study is supported by the , which aims to harness different strands of engineering and clinical developments in micro-robotics for precision surgery and to establish platform technologies for endoluminal micro-surgical intervention with broad values across different surgical specialties. The work is an integral part of developing the “fibre-bot” pioneered by the team, with integrated actuation, sensing and delivery channels for endoluminal micro-surgical tasks.

This research paper can be accessed via .

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