New research from Ohio State professor could potentially revolutionize the field of multifunctional robots and machines

Posted: December 9, 2019

Highlights of different uses of Professor Zhao
Highlights of different uses of Professor Zhao
New research from Ohio State assistant professor Renee Zhao can have an impact in a variety of fields from morphing antennas to soft robotics and even heart surgery.

The research focuses on creating shape-shifting soft materials that transform with the use of two types of embedded magnetic particles that are manipulated using remote-controlled electromagnetic fields. This new material is called the Magnetic Shape Memory Polymer.

It is building off Zhao’s previous research which used magnets as an actuation method to change the soft material into a different shape. The new material can be heated to make it pliable and then cooled to lock it to a desired shape, with the goal of creating a new class of materials that can be used across many different disciplines of engineering.

“The new functional soft material enables the development of new advanced material systems that could potentially revolutionize multifunctional robots and machines,” Zhao said.

Researcher Renee Zhao, postdoc Qiji Ze, Graduate student Shuai Wu pose with their research
Researcher Renee Zhao, postdoc Qiji Ze, Graduate student Shuai Wu pose with their research

The material actuation speed is based on the percentage of iron oxide in the polymers make-up. This allows for sequencing of when the material moves and locks, which can be used in electrical engineering for the creation of logic gates.

The material is adaptive to extreme conditions, which allows it for an array of uses, Zhao said.


“The degree of freedom is limited in conventional robotics,” Zhao said. “With soft materials, that degree of freedom is unlimited.”

Soft robotics is a subfield of robotics dealing with construction robots using material that can be controlled in very specific ways ­— often mimicking those found in living organisms. For example, the muscles that control an arm can be tighten, lengthen, and manipulated in a way that the user has complete control.

Creating materials like this does not come without its challenges, and because of this many existing soft materials only have one or two ways they can be manipulated.


“One of the big challenges in the soft active materials field is how to integrate various shape manipulations into one material system for multifunctional purposes, as many such manipulations are contradictory to each other,” Zhao said. “For example, fast reversible shape change requires that the material can respond to external stimulus rapidly, but shape locking needs the material to have no response or needs to maintain the external stimulus, which requires a constant energy input.”

To overcome these challenges, the team combined the advantages of magnetic soft active materials using strong magnets made with neodymium, shape memory polymers, and iron oxide.

The team used a high frequency magnetic field to heat and cool the shape memory polymer to make it changeable and lock it into place, and used a low frequency magnetic field to achieve multi-functional shape manipulation. 

Zhao believes that these materials could have in the biomedical field from heart surgery to drug delivery.

“This work opens up a lot of opportunities in the biomedical field for applications in minimally invasive surgeries,” said Zhao. “One future direction is to develop a system that can be potentially used in the human body.”

Besides, this research could have an impact on the fundamentals of science.

“From the fundamental science aspect, this research creates a new material that utilizes multi-physics responses for functional operations,” Zhao said. “The involved thermal, magnetic, and mechanical behavior generates a series of fundamental questions.”

This research highlights the interdisciplinary work being done within the Department of Mechanical and Aerospace Engineering and was published in the December 9th issue of Advanced Materials. The work was also selected as the front cover. Advanced Materials is considered one of the most prestigious journals in general material science.

The main contributors are postdoc Qiji Ze, students Shuai Wu and Rundong Zhang, from the Soft Intelligent Materials Lab, directed by Professor Ruike (Renee) Zhao at OSU, and postdoc Xiao Kuang, students Janet Wong and S. Macrae Montgomery from the Mechanics of Soft Active Materials and 3D Printing Lab, directed by Professor H. Jerry Qi at Georgia Tech.

The work is supported by the Haythornthwaite Foundation Research Initiation Grant, The Ohio State University Materials Research Seed Grant Program, funded by the Center for Emergent Materials, an NSF-MRSEC, grant DMR-1420451, the OSU Center for Exploration of Novel Complex Materials, the OSU Institute for Materials Research, AFOSR FA9550-19-1-0151, and US Department of Energy under Grant No. DE-SC0001304.

by Jake Rahe, Department of Mechanical and Aerospace Engineering