From the beginning until the end of the project, we have made key developments in the fabrication of magnetoelectric (ME) and piezoelectric (PE) materials for several micro and nanorobotic designs. (Adv. Funct. Mater. 2020, 30 (17), 1910323). Key innovations involve the tuning of the crystalline orientation of PE nanoparticles (NPs) for enhanced performance (Adv. Funct. Mater. 2022, 32 (35), 2202180), and the use of multiferroic core-shell NPs to trigger the hydrogen evolution reaction (Adv. Mater. 2022, 34 (19), 2110612) for future hydrogen therapies. We have also developed ME bilayers with enhanced magnetoelectric (ME) coupling. Within this particular research we have also discovered the occurence of the shape-memory effect in ME bilayers at nanoscale for the first time (Nat. Commun. 2023, 14 (1), 750). Finally, we have also discovered a novel way to generate ME: magnetopyroelectricity, which exploits magnetothermal efects to generate electrical fields (Mater. Horiz. 2023, 10 (7), 2627–2637). We have also developed porous materials (MOFs) coupled with piezoelectric shells. Various manipulation strategies and the fabrication of diverse micro-/nanorobots were explored, such as self-rolled designs, spherical, and helical devices.
We have also developed several magnetic catheter designs. In this last period, a microcatheter featuring a reservoir for nanorobot storage and deployment has been succesfully realized. Successful demonstrations included NP deployment and swarm locomotion in a phantom of the spinal cord recreating the cerebrospinal fluid dynamics.
Additionally, we've developed a table-top electromagnetic navigation system intended for future in vivo studies with small animals (rodents, rabbits). The successful magnetic navigation of micro- and nanorobots using this system has been validated, bridging the gap between laboratory innovation and preclinical utility.
Paying attention to biocompatibility, we created micro-/nanorobots from polymeric materials, e.g. biodegradable hydrogels (e.g. Adv. Funct. Mater. 2020, 30 (17), 1910323); polymers with tuneable stability (Adv. Funct. Mater. 2023, 2212952); and sucrose (Adv. Mater. 2020, 32 (52), 2005652.). We successfully developed (bio)templating methods for incorporating functional materials onto the templates, for example, for piezoelectric detoxification of protein aggregates (Nanoscale 2023, 15 (36), 14800–14808), and neuronal electrostimulation (Mater. Horiz. 2022, 9 (12), 3031–3038). We have also evaluated the biodegradation of ME nanomaterials and micro-/nanoswimmers to predict their lifespan in biological environments.
During the last period of the project, we conducted an in vivo demonstration of spinal cord injury (SCI) treatment,using an in vivo SCI model. We successfully verified the efficiency of our ME nanoparticles-based robots for SCI treatment by performing whole-mount immunohistochemistry of the SCI model. Moreover, successful in vivo magnetic navigation of dye labelled ME robots were demonstrated by effectively guiding them to the SCI site using developed table-top eMNS.
Our results have been disseminated in several international conferences (e.g. MRS, MARSS, Actuators) and we are now considering the possibility to create an startup for the exploitation of ME materials.
