Micropipette Resonator Enabling Targeted Aspiration and Mass Measurement of Single Particles and Cells

Abstract

This paper reports micropipette resonators, mechanical resonator-integrated micropipettes, which enable selective aspiration and mass measurement of particles or cells suspended in liquids with two orthogonal vibration modes. A custom pipette pulling system is built to provide power-modulated linear heating on a rotating glass capillary to make an asymmetric cross section with extended uniformity.A glass capillary is stretched with the custom puller, cut within the pulled region, polished, mounted on a machined metallic jig, and then coated with a metal. As a result, a doubly clamped tube resonator-integrated micropipette is made. For simultaneous frequency readouts of two orthogonal modes, an optical pickup, originally developed for optical data storage, is configured closely above and properly aligned to the micropipette resonator and two digital phase-locked loops are employed. For mass responsivity calibration, frequency shifts of the micropipette resonator are measured with various liquids and glass microparticles. Buoyant masses of unicellular organisms, Paramecium aurelia, freely swimming in a culture dish are successfully measured with two orthogonal modes.

Nanomechanical hydrodynamic force sensing using suspended microfluidic channels

“…2b ), which results in the detection of only one of them in a real experiment. This is the case for previous studies on SMR devices 16 , 17 , 30 , 40 , in which only the mass effect has been measured, implying that the force effect is negligible for the experimental conditions typically used. To determine which conditions are optimal to measure the hydrodynamic force effect, we study both limits of Eq.…”

Nanomechanical Molecular Mass Sensing Using Suspended Microchannel Resonators

“…This problem becomes even more dramatic for gases, as their density is not as well defined as in liquids due to their compressibility. To overcome this problem, transparent microcapillary resonators (TMR) have been developed to combine the highly sensitive mass density sensing, measured from its mechanical frequency signal [ 25 , 26 , 27 , 28 ], with refractive index measurements, obtained from its reflectivity signal with detection limit of 10 −5 [ 7 , 29 ].…”

Hydrodynamic Assisted Multiparametric Particle Spectrometry

“…Among the SMR devices, transparent microcapillary resonators (TMR) not only combine a nanomechanical resonator with a microfluidic channel but also allow the optical probing of the flowing particles. These devices have been demonstrated in previous works as an interesting alternative to cantilever-type SMRs for mass sensing [18][19][20][21][22][23] , introducing a new source of information about the particle based on its optical characterization 24,25 . This double mechanooptical particle detection technique has been proved in recent work as a highly reliable technique for particle discerning, even in cases of particles of similar masses.…”