CSIC has published a study that has obtained unprecedented active smart microstructures that could be applied to make cell cultures that emulate living tissues.
The combination of electrowriting and smart materials has resulted in a structure that can change shape or exert force in a controlled manner.
PRIME coordinator and CSIC researcher Carlos Sánchez Somolinos, from the Institute of Nanoscience and Materials of Aragon (INMA), a joint institute of the Spanish National Research Council (CSIC) and the University of Zaragoza (UNIZAR), is leading a new line of research, pioneered internationally, that combines melt electrowriting of smart materials for biomedical applications and soft robotics. For the first time, the researchers have used stimuli-sensitive active materials, leading to active biomimetic structures with mechanical functions that can be digitally programmed. The study is published in Advanced Materials and represents a pioneering finding that could provide the basis for realizing cell cultures that more accurately mimic living tissues.
“Fabricated with suitable materials, these structures could serve as mechanically active biomimetic scaffolds, as opposed to the passive ones currently used, providing, under appropriate stimulation, a scaffold in which the cultured cells feel the cyclic forces that they experience in living tissues, for example, the heart,” explains Sánchez Somolinos, who carried out the study with INMA researcher Mehrzad Javadzadeh, a doctoral student of UNIZAR in INMA, and Jesus del Barrio, professor at UNIZAR and researcher at 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 ultrathin liquid crystal elastomer fibers with diameters of just a few microns, as opposed to those of 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 molecular orientation control, enabling unprecedented smart microstructures with on-demand mechanical deformation to be obtained. “This work gives us the opportunity to explore the small,” summarizes Sánchez-Somolinos.
During the electrowriting process, the material acquires a preferred microscopic orientation that is key to precisely controlling the magnitude and direction of the forces that the material then exerts when heated. The 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 utility in areas such as soft robotics and biomedicine.
Currently, the electrowriting technique is employed by some 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.
Microstructuring with electrowriting of stimuli-responsive active materials, demonstrated in the present work, leads to active biomimetic structures with digitally programmed mechanical functions. “The aim is to achieve structures that emulate the extracellular matrix in the most representative way possible, i.e., three-dimensional and dynamic,” explains Sánchez-Somolinos.
Groundbreaking technique at the foundation of PRIME
This research strengthens CSIC’s already outstanding 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 fibers 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. Sánchez-Somolinos is also the coordinator of both projects.
PRIME pursues the implementation of microfluidic devices, chips with microchannels through which fluids can circulate controlled by these smart materials that are deposited by 4D printing. PRIME seeks to demonstrate the feasibility of this technology that could allow chemical analysis of fluids in a fast, inexpensive and portable way. Potential applications would include clinical analysis, water analysis or veterinary diagnostics.
The PRIME consortium congratulates Sánchez-Somolinos and his team for this highly impactful publication.
Mehrzad Javadzadeh, Jesús del Barrio, Carlos Sánchez-Somolino. Melt electrowriting of liquid crystal elastomer scaffolds with programmed mechanical response. Advanced Materials. 2022. DOI: https://doi.org/10.1002/adma.202209244