Apparatus and method for moving a liquid by means of a piezoelectric transducer

Inventors

Gabl, Reinhard • Link, Mathias • Schreiter, Matthias • Weber, Jan

Assignees

Biomensio Ltd

Abstract

An apparatus having a device for moving a liquid comprises a piezoacoustic resonator element (11) having at least one piezoelectric layer (110) and two electrodes (111 and 112) present on the piezoelectric layer (110). The piezoacoustic resonator element (11) is designed such that, owing to a voltage being applied to the piezoelectric layer (110) by means of the electrodes (111 or 112), a volume oscillation of the piezoelectric layer (110) is excited at a resonant frequency. The piezoelectric resonator element (11) can be acoustically coupled in a suitable manner to a liquid for the purpose of transmitting the excited oscillation into the liquid for the purpose of moving the liquid. The apparatus may be in the form of a micromixer or in the form of a micropump and may comprise, in addition, sensor elements (41) for detecting the attachment of substance.

Core Innovation

The invention provides an apparatus for disturbing a liquid in a channel by using at least one piezoacoustic resonator element having at least one piezoelectric layer and two electrodes. The piezoacoustic resonator element is affixed to a first interior wall of the channel between an inlet and an outlet so that the piezoelectric layer is exposed to the liquid. By applying a voltage to the piezoelectric layer via the electrodes, a volume oscillation of the piezoelectric layer is excited at a resonant frequency to disturb the liquid.

The disclosed resonator-based disturbance is characterized by exciting the volume oscillation at a resonant frequency and acoustically coupling the resonant oscillation into the liquid, with embodiments that enable longitudinal oscillation and shear oscillation. The document describes operation using different mode excitations and includes a piezoelectric layer configured to excite both longitudinal and shear mode volume oscillations. Additional embodiments include multi-resonator activation and activation using anti-phase operation.

The document also discloses miniaturized implementations in microfluidics such as a micromixer or a micropump, including embodiments on membranes and in packaged structures. Further embodiments combine actuator and sensor functionality, in which adsorption of a substance in or on a surface section in a channel causes a resonant frequency shift used for detection, including embodiments using DNA/biomolecule-specific coatings and gravimetric avidin sensing. The document additionally describes arrangements where actuator and sensor are combined in a stack or implemented using a single resonator by selecting a crystallographic orientation or tilt of piezoelectric materials.

Claims Coverage

The document provides one independent claim directed to an apparatus for disturbing a liquid using an in-channel piezoacoustic resonator element, with multiple dependent claims refining how the volume oscillation is excited and how resonance-related sensing features are implemented. The independent claim contains the core inventive concept of exposing a piezoelectric layer to the liquid in a channel and exciting resonant volume oscillation via two electrodes to disturb the liquid.

Overall claim coverage centers on an in-channel piezoacoustic resonator element that uses a voltage-applied piezoelectric layer, exposed to the liquid, to excite resonant volume oscillation that disturbs the liquid. Dependent claim refinements include specific excitation modes, resonance-frequency constraints, structural arrangements with membrane mounting and multi-element layouts, and adsorption-related sensing using resonant frequency shifts.

Stated Advantages

Documented Applications