In this paper, we propose a method that uses magnetic nanoparticles (MNPs) to detect, and also estimate sizes of rare cells using Hall-effect. Rare cells labeled with MNPs are detected in-flow using a pair of micro Hall voltage detectors (µHD). The voltage signals of µHD are then analyzed to obtain size estimates. No physical contact, stressing, electrical excitation or immobilizing of cells is used. Voltage variations based on sensor dimension, vertical and horizontal cell position and cell size were analyzed in simulations using finite element method. A signal processing algorithm was developed to determine cell size from detected voltages of bottom/top µHDs. This novel 2D dual µHD concept offers better accuracy when compared to conventional single µHD approach in cell count and also provide size profiling with 12.2% average error for cell diameters from 10 µm to 26 µm.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2014: MEMS, Fluidics, Bio Systems, Medical, Computational & Photonics
Published: June 15, 2014
Pages: 65 - 68
Industry sector: Sensors, MEMS, Electronics
Topics: MEMS & NEMS Devices, Modeling & Applications