Suspended microchannel resonators with piezoresistive sensors

Abstract

Precision frequency detection has enabled the suspended microchannel resonator (SMR) to weigh single living cells, single nanoparticles, and adsorbed protein layers in fluid. To date, the SMR resonance frequency has been determined optically, which requires the use of an external laser and photodiode and cannot be easily arrayed for multiplexed measurements. Here we demonstrate the first electronic detection of SMR resonance frequency by fabricating piezoresistive sensors using ion implantation into single crystal silicon resonators. To validate the piezoresistive SMR, buoyant mass histograms of budding yeast cells and a mixture of 1.6, 2.0, 2.5, and 3.0 mm diameter polystyrene beads are measured. For SMRs designed to weigh micron-sized particles and cells, the mass resolution achieved with piezoresistive detection ($3.4 fg in a 1 kHz bandwidth) is comparable to what can be achieved by the conventional optical-lever detector. Eliminating the need for expensive and delicate optical components will enable new uses for the SMR in both multiplexed and field deployable applications.

Numerical Analysis of Hydrodynamic Flow in Microfluidic Biochip for Single-Cell Trapping Application

“…The microchannel is modeled as 3D Eulerian explicit EC3DR and an eight-node linear Eulerian brick element part assigned with water properties (density, equation of state, and viscosity). A sphere-shaped yeast cell (5 μm in diameter) is modeled as an elastic 3D standard solid deformable C3D8R and an eight-node linear brick 3D part with the yeast properties (Young’s modulus, Poisson’s ratio, and density) obtained from literature [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ].…”

Geometrical considerations for the design of liquid-phase biochemical sensors using a cantilever's fundamental in-plane mode

“…Although the embedded fluid channel resonator offers single molecule resolution, it currently requires a complex fabrication process and can only be used with relatively low fluid flow rates (on the order of 1 μl/min at 10 bar of pressure). A piezoresistive read-out scheme has recently been demonstrated for the embedded fluid channel devices [19]. A similar method for Q enhancement has also been demonstrated using flexural plate resonators [20].…”

Resonant characteristics of rectangular hammerhead microcantilevers vibrating laterally in viscous liquid media

“…A piezoresistive read-out scheme has recently been demonstrated for the embedded fluid channel devices. 19 A similar method for Q enhancement has also been demonstrated using flexural plate resonators. 20 Finally, cantilever quality factors during liquid operation have been improved by placing the cantilever in a flow cell where only one side of the device is immersed, thus reducing the amount of energy loss to the fluid.…”