Magnetic spray robot

Magnetic spray turns objects into mini robots that can deliver drugs

By Ibrahim Sawal

The magnetic spray can animate small objects

Hong Kong City University

A glue-like magnetic spray can turn objects like pills into mini robots that can be controlled by magnets and navigated through the body.

The sprayed objects can be made to roll, turn and creep using a magnetic field. Shen Yajing of City University in Hong Kong and his colleagues even used the spray to animate the wings of an origami crane.

“Our spray can convert various tiny objects directly into mini robots,” says Yajing. The object can be flat or three-dimensional, he says, and all it takes is a thin layer of spray. The substance known as M-Spray consists of polyvinyl alcohol, gluten and iron particles.


The spray coating can be removed using an oscillating magnetic field to break it down into powder, leaving the object intact, says Yajing. This could come in handy for delivering pills to a specific location. The remaining powder can be absorbed or excreted by the body, says Yajing.

The team tested this by successfully maneuvering and dissolving a drug coated with M-spray onto a target area in the stomach of an unconscious rabbit.

“Since biocompatible components and side effects are negligible due to the degradation, it is a good candidate for biomedical applications,” says Xinyu Wu from the Shenzhen Institute of Advanced Technology, China.

Journal reference: Science Robotics, DOI: 10.1126 / scirobotics.abc8191

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