Analysis of MEMS-Based Microneedles for Blood Monitoring

Diseases such as measles, mumps, rubella, chicken pox, etc. are diagnosed using blood. Once the patients are diagnosed with such diseases, it is necessary to periodically monitor their blood. Currently, the patients are hospitalized for blood monitoring. However, in the developing worldwhere there is no access to hospitals, it is therefore necessary to have point-ofcare devices for monitoring. In this paper, we present a novel biocompatible and robust design of microelectromechanical systems (MEMS)-based microneedle tailored for point-of-care blood monitoring. The cross-sectional areas of the needle bores were optimized, taking into the account of the bending stress on the needle and the flow rate in the channel. Ni and polyethylene glycol diacrylate (PEGDA) coatings are provided to the poly-Si microneedles to have better strength and biocompatibility, respectively. The mechanical and fluidic models of the microneedle were solved numerically using COMSOL Multiphysics 4.2a. Based on the computational results, the designed microneedle is found to have capability to extract blood at the rate of 0.45 mu L/s and, hence, be made available for blood monitoring.