INMA researchers get through electro-writing a ‘live’ material that could mimic the heartbeat
The Aragonese CSIC researcher Carlos Sánchez Somolinos, from the Instituto de Nanociencia y Materiales de Aragón (INMA), a joint institute of the Consejo Superior de Investigaciones Científicas (CSIC) and the University of Zaragoza (UNIZAR), leads a new line of research, a pioneer at international level, which combines melt electro-writing of smart materials for biomedical applications and soft robotics. Researchers have used for the first time stimuli-responsive materials, leading to active biomimetic structures with digitally programmed mechanical functions. The results of this study have been published in the scientific journal Advanced Materials and represent a pioneering finding that could serve as a basis for realising cell cultures that more closely emulate living tissues.
Made of suitable materials, these structures could serve as mechanically active biomimetic scaffolds, as opposed to the currently used passive ones, providing, under appropriate stimulation, a scaffold in which the cultured cells feel the cyclic forces they experience in living tissues, for example, the heart. “The aim is to create structures that emulate the extracellular matrix in the most representative way possible, i.e. three-dimensional and dynamic,” explains Sánchez Somolinos, co-author of the article with Mehrzad Javadzadeh, a doctoral student at UNIZAR at the INMA, and Jesús del Barrio, a professor at UNIZAR and researcher at the INMA.
A pioneering technique worldwide
This novel microfabrication platform is applied for the first time in the world to liquid crystal elastomers, intelligent materials that respond mechanically to an external stimulus – in this case, temperature. The methodology presented has made it possible to digitally deposit ultra-thin liquid crystal elastomer fibres with diameters of just a few microns, as opposed to the hundreds of microns typically obtained by conventional 3D printing. As a result, microstructures of these materials have been obtained with very small dimensions that were previously inaccessible with other structuring techniques. The proposed new technique thus outperforms all current methodologies for microfabrication of these materials in terms of size and control of molecular orientation, giving access to unprecedented smart microstructures with on-demand mechanical deformation to be obtained. “This work gives us the opportunity to explore the world of small,” says Sánchez Somolinos.
During the electro-spinning process, the material acquires a preferred microscopic orientation that is key to precisely control the magnitude and direction of the forces that the material exerts when excited with temperature. Structures prepared with this new printing platform are intelligent in nature, deforming in a controlled manner in response to external stimuli, and have a remarkable ability to perform stresses and mechanical work of potential use in areas such as soft robotics and biomedicine.
Currently, the electro-spinning technique is being used by international biomedical research groups in combination with passive biocompatible materials, such as polycaprolactone, to prepare static scaffolds for cell culture that mimic the structural features found in native living tissues, such as myocardium.
This research strengthens CSIC’s already prominent position in the field of liquid crystal elastomers for soft robotics at the international level. Already in 2017, the Advanced Manufacturing Laboratory of INMA, led by Sánchez Somolinos, demonstrated for the first time the 4D printing of these materials, a technique that allows extruding and depositing fibres of the order of hundreds of microns to manufacture smart structures with liquid crystal elastomer materials. This work was the seed of two European projects coordinated by the CSIC, PRIME and STORM-BOTS.
In this sense, Sánchez Somolinos is also the coordinator of both. On the one hand, STORM-BOTS. aims to train 13 young researchers (three of them in Aragon) in the area of materials for soft robotics. The incorporation of smart materials, which respond with a significant change of one of their physical properties in response to an external stimulus (such as heat, light or an electric or magnetic field), constitutes in robotics an opportunity to develop new disruptive soft robotic elements and devices and can open up new possibilities in terms of designs, functions and responses, inaccessible to conventional hard robots. Developments in this area are expected to revolutionise the fields of minimally invasive surgery, material handling, electronic skin and human-machine interfaces.
On the other hand, PRIME is pursuing the implementation of microfluidic devices in which the circulation of fluids through microchannels is controlled by these smart materials can circulate and which are deposited by 4D printing. PRIME seeks to demonstrate the feasibility of this technology that could enable chemical analysis of fluids in a fast, inexpensive and portable way. Potential applications include clinical analysis, water analysis and veterinary diagnostics.
“Melt electrowriting of liquid crystal elastomer scaffolds with programmed mechanical response”
Mehrzad Javadzadeh, Jesús del Barrio, Carlos Sánchez-Somolinos
Advanced Materials
First published: 02 December 2022
DOI: 10.1002/adma.202209244
21/12/2022
