Nanofilms (or nanosheets) are polymer-based films with a very large area (up to tens of cm2) and with a thickness in the order of few tens – hundreds of nanometers. The peculiar properties of these structures make them suitable for different applications, such as electrochemical devices, and chemical, biological as well as nanomechanical sensors. Biocompatibility, flexibility and possibility to carry drugs for controlled release are just some of the most interesting features that nanosheets can offer. They have been recently presented in the biomedical field for closing incisions after open surgery or laparoscopic procedures, using them as nanopatches or adding them to traditional sutures on wet tissues.
In this field the CMBR research is mainly focused on new nano-composite films with magnetic and conductive properties that can be used for developing novel integrated microrobots and devices for biomedical applications.
In particular the possibility to finely position and manipulate nanofilms within wet or liquid working environments represents a key point. Since the use of magnetic fields to remotely control microdevices inside the human body is nowadays well accepted in surgical and diagnostic procedures, CMBR proposed this approach developing PLA/PLLA nanofilms embedding superparamagnetic iron oxide nanoparticles (SPIONs). The resulting nanofilms could be remotely controlled by permanent and gradient magnetic fields, thus opening new application scenarios, as already theoretically and experimentally demonstrated. By applying a similar approach, CMBR has developed original techniques for the obtainment of free-standing conductive nanofilms that can be manipulated, folded and unfolded in water many times without losing conductive properties.
Smart polymer actuators
Actuators represent the real bottleneck in many robotic applications, especially in micro and biomimetic ones. Currently available actuators are mainly electromagnetic and their performance is far from the one achieved, for example, by natural muscles. Main limitations involve inertia and back-drivability, stiffness control, power consumption. Anyway, in the last few years really new and promising technologies are emerging thus offering new possibilities to fill the gap between natural muscles and artificial artefacts. Smart polymers, with their almost infinite capability to be modified for the precise "tuning" of desired properties and with their generally easier and cheaper processing, represent key enabling technologies for micro-biorobotics. In this vision, CMBR research is mainly focused on studying new paradigms for actuation at the microscale, based on electronic-ionic conductive polymers (such as PEDOT/PSS) and liquid crystal elastomer (LCE) composites. In particular, concerning the electronic-ionic conductive polymers, a new bimorph actuator based on PEDOT/PSS - SU8 ultrathin composite film has been recently proposed and demonstrated, thus opening new exciting possibility for realization of microrobots and microdevices. In parallel CMBR is investigating new ways of transduction in LCE, coupling conductive properties or suitable electrodes to LCE surface, thus enabling more effective and efficient actuation.
This research aims at investigating the interaction of micro-nanostructured environments and materials with living cells and tissues. Several key aspects are investigated, including: micro-nanostructured scaffolding (based on polymeric nano-composite), and bio-nanotransducers (such as boron nitride nanotubes, barium titanate nanoparticles and zinc-oxide nanorods) for the development of bio-hybrid systems (artificial muscles, Merkel cells based devices), regenerative medicine (stem cells, neural cells, bone tissues) and nanomedicine (drug delivery, cell therapy).