Fabrication and Packaging of Flexible Polymeric Microantennae for in Vivo Magnetic Resonance Imaging

In this paper, we detail how microantennae dedicated to Magnetic Resonance Imaging (MRI) can benefit from the advantages offered by polymer substrates, especially flexibility and dielectric properties. We present a monolithic and wireless design based on the transmission lines between conductor windings on both sides of a dielectric substrate and its fabrication process. This last one requires specific plasma treatments to improve polymer/metal adhesion. We have led a comparative study on the effects of the ageing time on the wettability and the metal adhesion to Kapton and Teflon surfaces. Correlation between wettability (water contact angle) and adhesion (tensile strength) has been established. Then, the use of PolyDiMethylSiloxane (PDMS) as biocompatible packaging material and the optimization of its thickness allows us to conserve suitable f0 and Q values in a conducting environment such as the biological tissues. These studies allow us to perform 7 Tesla in vivo MRI of the rat brain with a high spatial resolution of 100 x 100 x 200 µm3 and a Signal to Noise Ratio of 80.

[1]  Thomas H. Mareci,et al.  Development of an inductively coupled MR coil system for imaging and spectroscopic analysis of an implantable bioartificial construct at 11.1 T , 2010, Magnetic resonance in medicine.

[2]  Thomas Schmitz-Rode,et al.  A monolithically fabricated flexible resonant circuit for catheter tracking in magnetic resonance imaging , 2010 .

[3]  R. R. A. Symsa,et al.  Thin-Film Detector System for Internal Magnetic Resonance Imaging , 2010 .

[4]  F. Massines,et al.  Effects of chemical composition and the addition of H2 in a N2 atmospheric pressure dielectric barrier discharge on polymer surface functionalization. , 2009, Langmuir : the ACS journal of surfaces and colloids.

[5]  Richard R. A. Syms,et al.  Catheter-based flexible microcoil RF detectors for internal magnetic resonance imaging , 2009 .

[6]  Joong-Kee Lee,et al.  Adhesion characteristics of copper thin film deposited on PET substrate by electron cyclotron resonance-metal organic chemical vapor deposition , 2008 .

[7]  A. Yung,et al.  Signal-to-noise ratio comparison of phased-array vs. implantable coil for rat spinal cord MRI. , 2007, Magnetic resonance imaging.

[8]  J. Grandchamp,et al.  Characterization of flexible RF microcoils dedicated to local MRI , 2007 .

[9]  Magnetic resonance microscopy of spinal cord injury in mouse using a miniaturized implantable RF coil , 2007, Journal of Neuroscience Methods.

[10]  Paul Crozat,et al.  Two- and three-dimensional microcoil fabrication process for three-axis magnetic sensors on flexible substrates , 2006 .

[11]  S. Fandrey,et al.  Mechanical and electrical properties of electroplated copper for MR-imaging coils , 2006 .

[12]  S. Megherbi,et al.  Behavioral VHDL-AMS model and experimental validation of a nuclear magnetic resonance sensor , 2005 .

[13]  A. Mata,et al.  Characterization of Polydimethylsiloxane (PDMS) Properties for Biomedical Micro/Nanosystems , 2005, Biomedical microdevices.

[14]  P. Tresco,et al.  Response of brain tissue to chronically implanted neural electrodes , 2005, Journal of Neuroscience Methods.

[15]  D. Brewis.  Adhesion to fluoropolymers , 2005 .

[16]  Qiang Chen.  Investigation of corona charge stability mechanisms in polytetrafluoroethylene (PTFE) teflon films after plasma treatment , 2003 .

[17]  B. Bein,et al.  The influence of mechanical adhesion of copper coatings on carbon surfaces on the interfacial thermal contact resistance , 2003 .

[18]  Richard L. Magin,et al.  NMR spiral surface microcoils: Design, fabrication, and imaging , 2003 .

[19]  Hervé Saint-Jalmes,et al.  Implantable planar rf microcoils for NMR microspectroscopy , 2002 .

[20]  M. Matlosz,et al.  Copper micromoulding process for NMR microinductors realization , 2002 .

[21]  K. Uğurbil,et al.  Microstrip RF surface coil design for extremely high‐field MRI and spectroscopy , 2001, Magnetic resonance in medicine.

[22]  Jean-Christophe Ginefri,et al.  Quick measurement of nuclear magnetic resonance coil sensitivity with a single-loop probe , 1999 .

[23]  Stéphane Serfaty,et al.  Multi‐turn split‐conductor transmission‐line resonators , 1997, Magnetic resonance in medicine.

[24]  J. Amouroux,et al.  Comparison of the efficiency of N2 and NH3 plasma treatments to improve the adhesion of PP films to in situ deposited Al coatings. Study of ageing phenomena in terms of acid-base properties , 1995 .

[25]  D. Bouchier,et al.  Role of helium plasma pretreatment in the stability of the wettability, adhesion, and mechanical properties of ammonia plasma-treated polymers. Application to the Al-polypropylene system , 1995 .

[26]  Frank D. Egitto,et al.  Plasma modification of polymer surfaces for adhesion improvement , 1994, IBM J. Res. Dev..

[27]  Luc Darrasse,et al.  Quick measurement of NMR‐coil sensitivity with a dual‐loop probe , 1993 .

[28]  D B Plewes,et al.  MR imaging of blood vessels with an intravascular coil , 1992, Journal of magnetic resonance imaging : JMRI.