2010

Authors

  • Tian Fook Kong Tian Fook Kong
  • Weng Kung Peng Weng Kung Peng
  • Trung-Dung Luong Trung-Dung Luong
  • Nam-Trung Nguyen Nam-Trung Nguyen
  • Jongyoon Han \ Jongyoon Han \

This paper reports the fabrication and characterization of an adhesive-based liquid-metal microcoil for magnetic resonce relaxometry (MRR). Conventiolly, microcoils are fabricated by various techniques such as electroplating, microcontact printing and focused ion beam milling. These techniques require considerable fabrication efforts and incur high cost. In this paper, we demonstrate a novel technique to fabricate three-dimensiol multilayer liquid-metal microcoils together with the microfluidic network by lamition of dry adhesive sheets. One of the unique features of the adhesive-based technique is that the detachable sample chamber can be disposed after each experiment and the microcoil can be reused without cross-contamition multiple times. The integrated microcoil has a low direct-current (DC) resistance of 0.3 O and a relatively high inductance of 67.5 nH leading to a high quality factor of approximately 30 at 21.65 MHz. The microcoil was characterized for [similar]0.5 T proton MRR measurements. The optimal pulse duration, amplitude, and frequency for the 90࠰ulse were 131 峬 -30 dB (1.56 W) and 21.6553 MHz, respectively. In addition, we used the liquid-metal microcoil to perform a parametric study on the transverse relaxation rate of human red blood cells at different hematocrit levels. The transverse relaxation rate increases quadratically with the hematocrit level. The results from the liquid-metal microcoil were verified by measurements with a conventiol solenoid coil.