CHROMA

MIn the context of an aging population, and with the advancement of medicine and biomedical engineering, more and more sophisticated biomedical implants have been developed. In France, for example, the number of total knee replacements increased by 33% between 2008 and 2013. If biocompatibility and longevity of materials improved, specific tailoring of implants to individuals remains still limited by the current medical imaging technology, which does not allow accurate in-vivo mechanical strain measurements in human tissues. Understanding mechanical behavior of healthy and diseased tissues has a wide range of applications, not only in designing better-integrated implants, but also in improving diagnosis and tailoring individualized treatments. The CHROMA project focuses on developing potentially implantable sensors that are highly sensitive to strains and stresses, simple to use, minimally invasive, and that provide an easy readout. The principle of the sensors relies on their nanoscale structure, which confers them unique optomechanical properties. Partners of CHROMA will design microcapsules that sense strain states and, accordingly, emit a fluorescent signal in the infrared. Working in this spectral range permits the detection of strain through highly scattering tissues. Partners will synthesize the new microcapsules, study the constitutive mechanical laws of the microcapsules by experimental and numerical approaches, and characterize their optical and thermal properties. As a proof of concept, they will also inject and test these microsensors in artificial polymeric membranes. For this purpose, CHROMA brings together two teams of simulation scientists and experimentalists who will combine their complementary skills in nanotechnologies, soft matter, experimental and theoretical optics, and theoretical solid mechanics, to design and study this novel class of sensors. A PhD student will be hired to design and synthesize the novel microcapsules and study their mechanical properties. A postdoctoral scientist will perform simulations on the mechanics of microcapsules. The CHROMA grant will support an interdisciplinary consortium that will train students and postdocs to fundamental research with clearly envisioned applications.