| Project Detail |
Innovative materials replace touch in biomedical devices
Our fingertips have the inherent ability to translate pressure-associated signals into touch or haptic sense. Conventional surgeries require the haptic sense of surgeons but in robot-assisted operations, this direct contact is lost. To address this issue, the ERC-funded MagnetoSense project proposes to develop a novel haptic sensor using magnetorheological elastomer (MRE) materials. MREs are soft and consist of particles that can be magnetised and change shape in the presence of an external magnetic field. Researchers aim to achieve the reverse: to use MRE deformation upon encounter with an object to trigger a magnetic field change, measurable by a sensor. This innovation is expected to find many applications in the biomedical and robotics field.
Sensorial and tacSensorial and tactile information represent the base of all surgical procedures in medicine. The vision sense has been and continues to be developed extensively by use of micro-cameras, MRI, X-rays and many others. Nonetheless, in many cases, the vision is not enough. The touch sense is necessary to identify the stiffness of the underlying organ or tissue and press more or less to perform a cut, remove a tumor or even move a catheter inside a curved vain. This stiffness is transmitted to the finger of the surgeon as a “pressure-deformation” information. This haptic sense is present naturally in our fingertips. Nevertheless, with the recent development of non-invasive techniques, the surgeon operates robotic devices that deliver optical information via a screen but loses all haptic information since his/her fingers are not in direct contact with the organ. The present project aims at proposing a novel material, a magnetorheological elastomer (MRE) membrane as a haptic sensor. MREs are soft elastomeric materials comprising magnetic particles thus being able to deform significantly upon application of an external magnetic field. Recently, it was shown that by fabricating them in exotic or slender geometries one can exploit their resulting instabilities to shape surfaces, induce programmable swelling and deswelling, or even create swimming microrobots and externally controllable catheters. All those applications use MREs as actuators. By contrast, here, we plan to exploit the reverse operation that of sensing, i.e. induce magnetic field changes via deformation. The principle lies in using the inherent magneto-mechanical coupling to induce readable magnetic fields when the MRE deforms. The reading of the fields can then be translated back to a deformation and a force thus being able to sense soft or stiff objects. The very soft nature of MREs will allow for a very sensitive measurement of forces as low as those felt by touching a soft gel or baby-skin. |
