Planar Electromechanical Oscillator for Gravimetric Particle Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current gravimetric detection devices using NEMS/MEMS oscillators face challenges in detecting particles in liquid media due to limited quality factor, large size, and high production costs, making them unsuitable for biological analyses and in vivo applications.
Innovation Solution
A gravimetric detection device with a plane electromechanical oscillator supported by solid parts or beams, vibrated in a Lamé or volume extension mode, integrated with a fluid channel and molecular recognition elements, allowing for high-quality factor detection in a fluid medium with reduced bulk and low production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a bi-embedded beam structure is used for gravimetric detection, then detection resolution is improved (7 zg), but the device becomes bulky and requires high vacuum conditions incompatible with biological applications
Solution Approach 1:
The patent replaces magnetostatic transduction with electrostatic transduction. The electrostatic actuation system uses electrodes positioned near the oscillator surface to generate electrostatic forces for actuation and detection, eliminating the need for magnetic fields and vacuum conditions, thereby enabling operation in aqueous biological environments while maintaining high detection resolution
Solution Approach 2:
The patent changes the operating conditions from high vacuum (10-10 Torr) to atmospheric pressure aqueous environment. This parameter change is achieved through electrostatic transduction which is compatible with liquid media, allowing the device to function in biological applications while maintaining gravimetric detection capability
2Measurement precision
If optical detection methods are used with microresonators in aqueous solutions, then detection capability is achieved, but the quality factor becomes low (Q≈3) due to liquid displacement and mechanical stress
Solution Approach 1:
The patent replaces optical detection with electrostatic detection. The electrostatic detection system measures changes in capacitance between the oscillator and electrodes, providing a direct electrical readout that is insensitive to liquid medium effects, thereby maintaining high quality factor (Q>1000) while enabling detection in aqueous solutions
3Adaptability or versatility
If electrostatic transduction is used for oscillator actuation, then operation in aqueous medium is enabled, but device bulk increases due to actuation electrode placement
Solution Approach 1:
The patent positions electrodes in the same plane as the oscillator rather than beneath it, transitioning from a three-dimensional stacked configuration to a two-dimensional planar configuration. This reduces the vertical footprint and overall device bulk while maintaining electrostatic coupling for actuation and detection in aqueous medium
4Ease of operation
If through-cavity structure is implemented in the oscillator, then fluid access is improved, but structural strength and vibration quality are compromised
Solution Approach 1:
The patent uses thin film structures with through-cavities that are carefully engineered to maintain structural integrity. The thin films are designed with appropriate thickness and material properties to withstand vibrational stresses while allowing fluid access through the cavities, achieving both fluid permeability and mechanical reliability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves a high quality factor and low minimum detectable mass, enabling real-time monitoring of physiological parameters and detection of toxic/pathogenic species in fluids, with a reduced footprint and cost, suitable for in vivo use.
Implementation Method 1
Any oscillator subjected to a force of vibration between itself in vibration. At certain frequencies, specific to each oscillator, the vibration amplitude is maximum. These frequencies are called 'resonant frequencies'.
Implementation Method 2
The oscillator is actuated and its vibration frequency is detected by electrostatic coupling
Implementation Method 3
This gravimetric detection is generally based on the detection of variations in the vibration frequency of an electromechanical oscillator when a molecule is deposited on its surface.
Data Source
Figure 1~2
Figure 3~4
Figure 5~8
AI summary
The invention provides a device for the gravimetric detection of particles in a fluid medium, simultaneously providing a high quality factor, easier operating conditions, small size and low production costs. For this purpose, the subject of the invention is a device for the gravimetric detection of particles in a fluid medium, comprising a flat electromechanical oscillator (1), means for supporting the oscillator and means for actuating said oscillator, said means being designed to ensure that the oscillator (1) vibrates in its plane, said device further including a channel (4) for passage of the fluid, said channel being in fluid communication with a through-cavity (1b) made in said oscillator.