@article {2896, title = {A bioreactor with an electro-responsive elastomeric membrane for mimicking intestinal peristalsis}, journal = {Bioinspiration \& Biomimetics}, volume = {12}, year = {2016}, abstract = {

This study describes an actuated bioreactor which mimics the pulsatile contractile motion of the intestinal barrier using electro-responsive elastomers as smart materials that undergo deformation upon electrical stimulation. The device consists of an annular dielectric elastomer actuator working as a radial artificial muscle able to rhythmically contract and relax a central cell culture well. The bioreactor maintained up to 4 h of actuation at a frequency of 0.15 Hz and a strain of 8\%{\textendash}10\%, to those of the cyclic contraction and relaxation of the small intestine. In vitro tests demonstrated that the device was biocompatible and cell-adhesive for Caco-2 cells, which formed a confluent monolayer following 21 days of culture in the central well. In addition, cellular adhesion and cohesion were maintained after 4 h of continuous cyclic strain. These preliminary results encourage further investigations on the use of dielectric elastomer actuation as a versatile technology that might overcome the limitations of commercially available pneumatic driving systems to obtain bioreactors that can cyclically deform cell cultures in a biomimetic fashion.

}, url = {http://iopscience.iop.org/article/10.1088/1748-3190/12/1/016001/pdf}, author = {D. Cei and J. Costa and G. Gori and G. Frediani and C. Domenici and F. Carpi and A. Ahluwalia} } @article {2242, title = {Enabling variable-stiffness hand rehabilitation orthoses with dielectric elastomer transducers}, journal = {Medical Engineering and Physics}, volume = {36}, year = {2014}, pages = {205{\textendash}211}, abstract = {

Patients affected by motor disorders of the hand and having residual voluntary movements of fingers or wrist can benefit from self-rehabilitation exercises performed with so-called dynamic hand splints. These systems consist of orthoses equipped with elastic cords or springs, which either provide a sustained stretch or resist voluntary movements of fingers or wrist. These simple systems are limited by the impossibility of modulating the mechanical stiffness. This limitation does not allow for customizations and real-time control of the training exercise, which would improve the rehabilitation efficacy. To overcome this limitation, {\textquoteright}active{\textquoteright} orthoses equipped with devices that allow for electrical control of the mechanical stiffness are needed. Here, we report on a solution that relies on compact and light-weight electroactive elastic transducers that replace the passive elastic components. We developed a variable-stiffness transducer made of dielectric elastomers, as the most performing types of electromechanically active polymers. The transducer was manufactured with a silicone film and tested with a purposely-developed stiffness control strategy that allowed for electrical modulations of the force-elongation response. Results showed that the proposed new technology is a promising and viable solution to develop electrically controllable dynamic hand orthoses for hand rehabilitation. ? 2013 IPEM.

}, doi = {10.1016/j.medengphy.2013.10.015}, author = {F. Carpi and G. Frediani and C. Gerboni and J. Gemignani and D. De Rossi} } @article {2241, title = {Wearable Wireless Tactile Display for Virtual Interactions with Soft Bodies}, journal = {Frontiers in Bioengineering and Biotechnology}, volume = {2}, year = {2014}, abstract = {

We describe here a wearable, wireless, compact, and lightweight tactile display, able to mechanically stimulate the fingertip of users, so as to simulate contact with soft bodies in virtual environments. The device was based on dielectric elastomer actuators, as high-performance electromechanically active polymers. The actuator was arranged at the user{\textquoteright}s fingertip, integrated within a plastic case, which also hosted a compact high-voltage circuitry. A custom-made wireless control unit was arranged on the forearm and connected to the display via low-voltage leads. We present the structure of the device and a characterization of it, in terms of electromechanical response and stress relaxation. Furthermore, we present results of a psychophysical test aimed at assessing the ability of the system to generate different levels of force that can be perceived by users.

}, keywords = {Bioengineering}, doi = {10.3389/fbioe.2014.00031}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4150388/}, author = {G. Frediani and D. Mazzei and D. De Rossi and F. Carpi} }