Digital acoustic flow control chip, preparation method and multi-dimensional sample processing method

Abstract

The invention discloses a digital acoustic fluidic chip, a preparation method and a multi-dimensional sample processing method, the digital acoustic fluidic chip comprises an upper polar plate and a lower polar plate, and the upper polar plate comprises a glass layer, a coating layer and an upper hydrophobic layer which are arranged in sequence; the lower polar plate comprises a lower hydrophobic layer, a dielectric layer, an electrode layer and a substrate which are arranged in sequence; the electrode layer comprises an EWOD pin electrode, a driving electrode, a sound wave pin electrode and an interdigital transducer; the interdigital transducer comprises a sound field and electric field multiplexing module, a sound standing wave field and thermal field module, a focusing sound field and thermal field module and a sound vortex enrichment module; each driving electrode is connected with one EWOD pin electrode, the two sides of the sound field and electric field multiplexing module, the two sides of the sound standing wave field and thermal field module, the two sides of the focusing sound field and thermal field module and the two sides of the sound vortex enrichment module are all connected with the two sound wave pin electrodes, and one side of the sound field and electric field multiplexing module is further connected with one EWOD pin electrode. The method has the advantages of multi-dimensional sample treatment and high-flexibility treatment.

Description

Technical Field

[0001] This invention relates to the fields of acoustic fluid control and digital microfluidics, and particularly to a digital acoustic fluid control chip, its fabrication, and a multi-dimensional sample processing method. Background Technology

[0002] Digital microfluidics (DMF) is a liquid handling technology that enables precise manipulation of minute amounts of liquid droplets, allowing for operations such as dispensing, moving, merging, and splitting. Currently, the most popular DMF technology utilizes electrowetting, offering fast response times, system simplicity, and high precision, providing significant advantages in reducing reagent usage, rapid reactions, and high throughput. However, most current microfluidic chips have limited functionality, only capable of simple liquid movement, resulting in limited manipulation and sample processing capabilities. Tasks such as droplet mixing, cell heating, and manipulating samples carried within droplets face significant challenges. Surface acoustic wave (SAW) technology based on MEMS processes offers advantages over other external fields, including ease of integration, low cost, non-destructive and non-contact operation. Furthermore, the acoustic field can generate various effects with the fluid and the carried biological sample, making it highly suitable for multi-dimensional biochemical analysis applications. This has led to the recent development of the emerging field of acoustic fluid dynamics. For example, surface acoustic wave (SAW) technology based on lithium niobate substrates enables flexible sample manipulation, arrangement, oscillation, and eddy current generation for mixing in microfluidics. Furthermore, based on various effects of acoustic fluid control, including acoustic radiation, acoustic flow, and acoustic heat, it can realize a variety of biochemical analysis applications, such as cell sorting, cell lysis, and nucleic acid reaction enhancement, demonstrating enormous potential in sample processing. However, despite the numerous capabilities and significant advantages that acoustic fluid control technology has demonstrated in biochemical analysis, key challenges remain in how to highly integrate multi-dimensional and multi-scale sample processing with biochemical analysis capabilities to build a universal and miniaturized platform. Specifically, most acoustic fluid control devices still require integration with microfluidic chips, relying on fluid-driven execution functions and necessitating additional fluid control equipment, facing the aforementioned bottlenecks in integration and automation. Secondly, current acoustic fluid control devices are designed for specific functions and cannot be applied to different needs, lacking versatility and flexibility.

[0003] In summary, digital microfluidics currently lacks the ability to couple multi-dimensional sample processing and analysis in a highly integrated manner. While acoustic fluid control technology has multi-dimensional sample processing capabilities, it still lacks the ability to highly integrate it with the DMF platform, as well as the technology to achieve diverse and flexible electrode design and modulation coupling of acoustic and thermal fields within the DMF platform, thereby enabling different functions and applications. Summary of the Invention

[0004] In view of this, the purpose of this invention is to propose a digital acoustic fluid control chip that combines digital microfluidics and surface acoustic wave technology to achieve electrode design, integration, and coupling control of electric field, sound field, and thermal field. The entire chip has the characteristics of high integration and miniaturization, and has the advantages of multi-dimensional sample processing and highly flexible processing.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by this invention is as follows: This invention provides a digital acoustic fluid control chip, comprising a bipolar plate structure consisting of an upper electrode plate and a lower electrode plate. The upper electrode plate includes a glass layer, a coating layer, and an upper hydrophobic layer arranged sequentially from top to bottom. The lower electrode plate includes a lower hydrophobic layer, a dielectric layer, an electrode layer, and a substrate arranged sequentially from top to bottom. The electrode layer includes multiple EWOD pin electrodes, multiple driving electrodes, multiple acoustic wave pin electrodes, and interdigital transducers. The interdigital transducers include an acoustic field and electric field multiplexing module, an acoustic standing wave field and thermal field module, a focused acoustic field and thermal field module, and an acoustic eddy current enrichment module. Each driving electrode is connected to one EWOD pin electrode. Both sides of the acoustic field and electric field multiplexing module, both sides of the acoustic standing wave field and thermal field module, both sides of the focused acoustic field and thermal field module, and both sides of the acoustic eddy current enrichment module are connected to two acoustic wave pin electrodes. One side of the acoustic field and electric field multiplexing module is also connected to one EWOD pin electrode.

[0006] Furthermore, the multiple driving electrodes are distributed within the liquid storage area, the droplet transport area, and the acoustic wave working area. The liquid storage area, droplet transport area, and acoustic wave working area are located in the central region of the electrode layer. The liquid storage area is located at the upper end of the central region and is used to store the initial droplet sample. The droplet transport area is distributed between the liquid storage area and the acoustic wave working area. A part of the droplet transport area is connected to the liquid storage area and is used to extract droplets from the liquid storage area and enter the droplet transport area. Another part of the droplet transport area is connected to the acoustic wave working area and is used to transport droplets to the acoustic wave working area for processing. The acoustic wave working area is located in the core functional area of ​​the electrode layer, close to the interdigital transducer. The driving electrodes in the liquid storage area, droplet transport area, and acoustic wave working area are all connected to the EWOD pin electrodes.

[0007] Furthermore, the plurality of driving electrodes includes a liquid storage electrode group distributed in the liquid storage area, a transport electrode group distributed in the droplet transport area, and a working electrode group distributed in the acoustic wave working area. The liquid storage electrode group includes a first liquid storage electrode, a second liquid storage electrode, and a third liquid storage electrode. The transport electrode group includes a first longitudinal transport section consisting of two transport electrodes connected longitudinally, a second longitudinal transport section consisting of two transport electrodes connected longitudinally, a third longitudinal transport section consisting of two transport electrodes connected longitudinally, a transverse transport section consisting of eight transport electrodes connected laterally, a first connecting transport section consisting of one transport electrode, a second connecting transport section consisting of one transport electrode, a second connecting transport section consisting of one transport electrode, and a fourth connecting transport section consisting of one transport electrode. The working electrode group includes a first working electrode, a second working electrode, and a third working electrode. The first, second, and third liquid storage electrodes are located on the same horizontal line. The lower end of the first liquid storage electrode is connected to the upper end of the first longitudinal transport section, the lower end of the second liquid storage electrode is connected to the upper end of the second longitudinal transport section, and the lower end of the third liquid storage electrode is connected to the upper end of the third longitudinal transport section. The upper end of the leftmost transport electrode in the transverse transport section is connected to the lower end of the first longitudinal transport section, and the upper end of the rightmost transport electrode in the transverse transport section is connected to the lower end of the third longitudinal transport section, with its right end connected to the left end of the sound field and electric field multiplexing module. The upper end of the fourth transport electrode from left to right in the transverse transport section is connected to the lower end of the second longitudinal transport section. The right end of the first connecting transport section is connected to the transverse transport section. The left end of the leftmost transport electrode in the transport section, the upper end of the second connecting transport section is connected to the lower end of the fourth transport electrode from left to right in the transverse transport section, the upper end of the third connecting transport section is connected to the lower end of the rightmost transport electrode in the transverse transport section, and the left end of the fourth connecting transport section is connected to the right end of the sound field and electric field multiplexing module; the right end of the first working electrode is connected to the left end of the first connecting transport section, and its upper and lower ends are connected to the acoustic eddy current enrichment module; the upper end of the second working electrode is connected to the lower end of the second oblique transport section, and its left, right and lower ends are all connected to the acoustic standing wave field and thermal field module; the upper end of the third working electrode is connected to the lower end of the third oblique transport section, and its lower end is connected to the focusing sound field and thermal field module; Each electrode in the liquid storage electrode group, transport electrode group, and working electrode group is a square or rectangular structure, and the area of ​​a single electrode in the liquid storage electrode group is greater than the area of ​​a single electrode in the working electrode group and greater than the area of ​​a single electrode in the transport electrode group.

[0008] Furthermore, the sound field and electric field multiplexing module is composed of a single interdigital electrode, with two pins of the interdigital electrode connected to two acoustic wave pin electrodes respectively, and one of the pins of the interdigital electrode also connected to an EWOD pin electrode.

[0009] Furthermore, the acoustic standing wave field and thermal field module consists of three interdigitated electrodes arranged in a cross pattern, respectively located at the left, right, and lower ends of the second working electrode, with each interdigitated electrode having two pins connected to two acoustic wave pin electrodes.

[0010] Furthermore, the focused sound field and thermal field module consists of a set of concentric sector-shaped interdigital electrodes, with the center of the circle located on the third working electrode. The two pins of the set of concentric sector-shaped interdigital electrodes are respectively connected to two acoustic wave pin electrodes.

[0011] Furthermore, the acoustic eddy current enrichment module consists of two right-angled trapezoidal interdigitated electrodes. The right-angled side of the upper right-angled trapezoidal interdigitated electrode is located at the upper end of the first working electrode, and the right-angled side of the lower right-angled trapezoidal interdigitated electrode is located at the lower end of the first working electrode. The two right-angled trapezoidal interdigitated electrodes have a rotationally symmetrical structure, with the center point of rotation being the center point of the first working electrode. The rotation angle is 180 degrees, that is, the upper right-angled trapezoidal interdigitated electrode rotates 180° along the center point of the first working electrode to form the lower right-angled trapezoidal interdigitated electrode. The two pins of each right-angled trapezoidal interdigitated electrode are respectively connected to two acoustic wave pin electrodes.

[0012] Furthermore, the dielectric layer is SU-8 photoresist, the upper and lower hydrophobic layers are both Teflon layers, the coating layer is an ITO layer, the substrate is a lithium niobate substrate, and the glass layer is a sodium-calcium-based or silicon-boron-based substrate.

[0013] This invention also provides a method for fabricating a digital acoustic fluid control chip, comprising the following steps: Upper electrode preparation: A coating layer and an upper hydrophobic layer are sequentially coated on the lower surface of the glass layer; Lower electrode preparation: 1) Fabricate corresponding chip samples on a substrate using photolithography; 2) An electrode layer is fabricated on a chip sample using a thin-film deposition process. The electrode layer includes multiple EWOD pin electrodes, multiple driving electrodes, multiple acoustic wave pin electrodes, and interdigital transducers. Each interdigital transducer includes an acoustic field and electric field multiplexing module, an acoustic standing wave field and thermal field module, a focused acoustic field and thermal field module, and an acoustic eddy current enrichment module. Each driving electrode is connected to one EWOD pin electrode. Both sides of the acoustic field and electric field multiplexing module, both sides of the acoustic standing wave field and thermal field module, both sides of the focused acoustic field and thermal field module, and both sides of the acoustic eddy current enrichment module are connected to two acoustic wave pin electrodes. One side of the acoustic field and electric field multiplexing module is also connected to one EWOD pin electrode. 3) Using a photoresist removal process, the chip sample is placed in acetone, anhydrous ethanol and deionized water respectively for ultrasonic treatment to remove the photoresist and obtain the patterned target chip. 4) Apply a dielectric layer to the area of ​​the target chip, excluding the EWOD pin electrode and the acoustic wave pin electrode, using photolithography. 5) Coat the area on the dielectric layer except for the EWOD pin electrode and the acoustic wave pin electrode with a hydrophobic layer; The upper and lower electrode plates are bonded together with spacer tape to form a complete digital acoustic fluid control chip.

[0014] This invention also provides a multi-dimensional sample processing method for a digital acoustic flow control chip, comprising the following steps: Inject the droplet sample into the reservoir area and fill the gap between the upper and lower electrodes with silicone oil or air. The droplet sample is split into smaller droplets by driving electrodes and moved from the droplet transport region to the acoustic working region; An acoustic signal is applied to the acoustic working area. The arrangement, oscillation and heating of particles in the droplet sample are realized through the acoustic standing wave field and thermal field module. The mixing and heating of two droplet samples and the acceleration of the droplet sample reaction are realized through the focusing acoustic field and thermal field module. The particles in the droplet sample are enriched through the acoustic eddy current enrichment module. The movement of the droplet sample and the mixing and heating of particles in the droplet sample are realized through the acoustic field and electric field multiplexing module.

[0015] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. Digital microfluidics and surface acoustic wave technologies are integrated on a lithium niobate-based digital acoustic fluid control chip, overcoming the shortcomings of traditional digital microfluidic chips that have a single dimension of control and sample processing. Electrode design, integration, and coupling control of electric field, acoustic field, and thermal field are realized. The entire chip has the characteristics of high integration and miniaturization, and different interdigital transducers can be designed according to different experimental requirements. Different acoustic fields can be selectively integrated on the chip, which has multi-dimensional sample processing and high flexibility.

[0016] 2. The digital acoustic fluid control chip of this invention can realize the basic functions of a digital microfluidic chip, enabling high-precision droplet manipulation and high-throughput parallel processing of droplets, exhibiting high flexibility and programmability in droplet control. Furthermore, this invention can generate different sound fields within a droplet sample moving on the driving electrode, achieving various precise manipulations of the sample within the droplet, including functions such as sample arrangement, oscillation, mixing, enrichment, and heating, offering advantages in multi-dimensional sample processing and highly flexible handling. Moreover, by designing different interdigital transducer structures, the acoustic-thermal effect can be modulated by controlling the amplitude of the input signal, achieving targeted heating at specific locations.

[0017] 3. This invention also provides a specific method for fabricating a digital acoustic fluid control chip and processing multi-dimensional samples. This method can quickly form a digital acoustic fluid control chip and control the droplet manipulation of the driving electrodes in the chip, as well as the acoustic and thermal field effects in the droplets, through signal modulation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a digital acoustic flow control chip provided in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the electrode layer structure in a digital acoustic flow control chip provided in an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of the driving electrode in the electrode layer provided in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the structure of the interdigital transducer in the electrode layer provided in the embodiment of the present invention (where a represents the structure diagram of the acoustic field and electric field multiplexing module, b represents the structure diagram of the acoustic standing wave field and thermal field module, c represents the structure diagram of the focused acoustic field and thermal field module, and d represents the structure diagram of the acoustic eddy current enrichment module).

[0023] Figure 5 This is a driving principle diagram of a digital acoustic flow control chip provided in an embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram of the manipulation of microparticles in a droplet by an interdigital transducer provided in an embodiment of the present invention (where a represents a physical diagram of the electrode layer, b represents an enlarged view of the second working electrode in the acoustic working area, c represents an effect diagram of the acoustic eddy current enrichment module, d represents an effect diagram of the focused acoustic field and thermal field module, and e represents an effect diagram of the acoustic standing wave and thermal field module).

[0025] Explanation of the labels in the diagram: 100-Upper electrode plate, 101-Glass layer, 102-Coating layer, 103-Upper hydrophobic layer, 200-Lower electrode plate, 201-Lower hydrophobic layer, 202-Dielectric layer, 203-Electrode layer, 204-Substrate, 1-EWOD pin electrode, 2-Drive electrode, 21-Reservoir region, 211-First reservoir electrode, 212-Second reservoir electrode, 213-Third reservoir electrode, 22-Droplet transport region, 221-First longitudinal transport section, 222-Second longitudinal transport section, 223-Third longitudinal transport section 224-Transportation Department, 225-First Connecting Transportation Department, 226-Second Connecting Transportation Department, 227-Second Connecting Transportation Department, 228-Fourth Connecting Transportation Department, 23-Acoustic Working Area, 231-First Working Electrode, 232-Second Working Electrode, 233-Third Working Electrode, 3-Acoustic Pin Electrode, 4-Interdigital Transducer, 41-Acoustic Field and Electric Field Multiplexing Module, 42-Acoustic Standing Wave Field and Thermal Field Module, 43-Focused Acoustic Field and Thermal Field Module, 44-Acoustic Vortex Enrichment Module. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the invention. Similarly, the following embodiments are only some, not all, embodiments of the present invention, and all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see Figures 1-6 The present invention provides a digital acoustic fluid control chip, comprising a bipolar plate structure consisting of an upper electrode plate 100 and a lower electrode plate 200. The upper electrode plate 100 comprises a glass layer 101, a coating layer 102, and an upper hydrophobic layer 103 arranged sequentially from top to bottom. The lower electrode plate 200 comprises a lower hydrophobic layer 201, a dielectric layer 202, an electrode layer 203, and a substrate 204 arranged sequentially from top to bottom. The electrode layer 203 includes multiple EWOD (electrowetting on dielectric) pin electrodes 1, multiple driving electrodes 2 for driving droplet movement and splitting, multiple acoustic pin electrodes 3, and interdigital transducers 4. The interdigital transducers 4 include an acoustic field and electric field multiplexing module 41, an acoustic standing wave field and thermal field module 42, a focused acoustic field and thermal field module 43, and an acoustic eddy current enrichment module 44. Each driving electrode 2 is connected to one EWOD pin electrode 1. Both sides of the acoustic field and electric field multiplexing module 41, both sides of the acoustic standing wave field and thermal field module 42, both sides of the focused acoustic field and thermal field module 43, and both sides of the acoustic eddy current enrichment module 44 are connected to two acoustic pin electrodes 3. One side of the acoustic field and electric field multiplexing module 41 is also connected to one EWOD pin electrode 1.

[0028] In this embodiment, the plurality of driving electrodes 2 are distributed within the liquid storage area 21, the droplet transport area 22, and the acoustic working area 23. EWOD technology enables the generation, splitting, fusion, and transport of droplets on the driving electrodes 2. The liquid storage area 21, the droplet transport area 22, and the acoustic working area 23 are located in the central region of the electrode layer 203. The liquid storage area 21 is located at the upper end of the central region and is used to store the initial droplet sample. The droplet transport area 22 is distributed between the liquid storage area 21 and the acoustic working area 23. Between them, a portion of the droplet transport region 22 is connected to the liquid storage region 21, used to extract droplets from the liquid storage region 21 and enter the droplet transport region 22. Another portion of the droplet transport region 22 is connected to the acoustic wave working region 23, used to transport droplets to the acoustic wave working region 23 for processing. The acoustic wave working region 23 is located in the core functional area of ​​the electrode layer 203, close to the interdigital transducer 4. The driving electrodes 2 in the liquid storage region 21, the droplet transport region 22, and the acoustic wave working region 23 are all connected to the EWOD pin electrode 1. The driving electrodes 2 in the liquid storage region 21 are used to store droplet samples. The liquid storage capacity of a single driving electrode 2 in the liquid storage region 21 is much higher than that of a single driving electrode 2 in the droplet transport region 22. By controlling the energizing state of different driving electrodes 2, the liquid storage region 21 and the droplet transport region 22 work together to achieve droplet pinching, generating small droplets suitable for transport and reaction from large droplets. The driving electrode 2 in the droplet transport region 22 is square, rectangular, or other shapes suitable for droplet movement, and can be used to clamp large droplets or move droplet samples. The driving electrode 2 in the acoustic working region 23 is the specific site for droplet sample reaction. It is close to the interdigital transducer 4, and its specific structural design is determined by the corresponding interdigital transducer 4. Its droplet control method is the same as that of other driving electrodes 2.

[0029] In this embodiment, the plurality of driving electrodes 2 include a liquid storage electrode group distributed in the liquid storage area 21, a transport electrode group distributed in the droplet transport area 22, and a working electrode group distributed in the acoustic wave working area 23. The liquid storage electrode group includes a first liquid storage electrode 211, a second liquid storage electrode 212, and a third liquid storage electrode 213 (the driving electrode 2 located in the liquid storage area 21 is the liquid storage electrode). The transport electrode group includes a first longitudinal transport section 221 longitudinally connected by two transport electrodes (the driving electrode 2 located in the droplet transport area 22 is the transport electrode), and a second longitudinal transport section 221 longitudinally connected by two transport electrodes. The system comprises two longitudinal transport sections 222, a third longitudinal transport section 223 consisting of two transport electrodes connected longitudinally, a transverse transport section 224 consisting of eight transport electrodes connected transversely, a first connecting transport section 225 consisting of one transport electrode, a second connecting transport section 226 consisting of one transport electrode, a second connecting transport section 227 consisting of one transport electrode, and a fourth connecting transport section 228 consisting of one transport electrode. The working electrode group includes a first working electrode 231, a second working electrode 232, and a third working electrode 233 (the driving electrode 2 located within the acoustic wave working area 23 is the working electrode). The first liquid storage electrode 211, the second liquid storage electrode 212, and the third liquid storage electrode 213 are located on the same horizontal line. The lower end of the first liquid storage electrode 211 is connected to the upper end of the first longitudinal transport section 221, the lower end of the second liquid storage electrode 212 is connected to the upper end of the second longitudinal transport section 222, and the lower end of the third liquid storage electrode 213 is connected to the upper end of the third longitudinal transport section 223. The upper end of the leftmost transport electrode in the transverse transport section 224 is connected to the lower end of the first longitudinal transport section 221, and the upper end of the rightmost transport electrode in the transverse transport section 224 is connected to the lower end of the third longitudinal transport section 223, with its right end connected to the left end of the sound field and electric field multiplexing module 41. The upper end of the fourth transport electrode from left to right in the transverse transport section 224 is connected to the lower end of the second longitudinal transport section 222. The right end of the first connecting transport section 225 is connected to the left end of the leftmost transport electrode in the transverse transport section 224. The upper end of the second connecting transport section 226 is connected to the lower end of the fourth transport electrode from left to right in the transverse transport section 224. The upper end of the third connecting transport section 227 is connected to the lower end of the rightmost transport electrode in the transverse transport section 224. The left end of the fourth connecting transport section 228 is connected to the right end of the acoustic field and electric field multiplexing module 41. The right end of the first working electrode 231 is connected to the left end of the first connecting transport section 225, and its upper and lower ends are connected to the acoustic eddy current enrichment module 44. The upper end of the second working electrode 232 is connected to the lower end of the second oblique connecting transport section 226, and its left, right, and lower ends are all connected to the acoustic standing wave field and thermal field module 42. The upper end of the third working electrode 233 is connected to the lower end of the third oblique connecting transport section 227, and its lower end is connected to the focusing acoustic field and thermal field module 43. By applying voltage to the driving electrode 2, the interfacial tension between the droplet and the surface of the digital acoustic fluid control chip can be changed, thereby changing the contact angle of the droplet. As the voltage increases, the contact angle of the droplet decreases, and the droplet is pulled towards the energized electrode, thus enabling droplet movement. EWOD technology can be used to realize the generation, splitting, fusion, and transport of droplets.

[0030] Each electrode (driving electrode, specifically: the first / second / third storage electrode in the storage electrode group, the transport electrode in the transport electrode group, and the first / second / third working electrode in the working electrode group) in the liquid storage electrode group, transport electrode, and working electrode group is a square or rectangular structure, and the area of ​​a single electrode in the liquid storage electrode group is greater than the area of ​​a single electrode in the working electrode group and greater than or equal to the area of ​​a single electrode in the transport electrode group.

[0031] In this embodiment, the acoustic and electric field multiplexing module 41 is composed of a single interdigital electrode 40. Two pins of the interdigital electrode 40 are respectively connected to two acoustic wave pin electrodes 3, and one pin of the interdigital electrode 40 is also connected to an EWOD pin electrode 1. By applying a high-voltage electric field or acoustic wave signal, droplet driving or acoustic field generation can be achieved, and the mixing of particles in the droplet can be accelerated and the droplet heated.

[0032] In this embodiment, the acoustic standing wave field and thermal field module 42 consists of three interdigitated electrodes 40 arranged in a cross pattern, respectively positioned at the left, right, and lower ends of the second working electrode 232. Each interdigitated electrode 40 has two pins connected to two acoustic wave pin electrodes 3. By applying a signal with a corresponding resonant frequency, a standing wave field can be generated in the droplet above the second working electrode 232. Particles or cells in the standing wave field are acted upon by acoustic radiation forces, moving towards nodes or antinodes. By modulating the combination of acoustic wave signals and phase differences, stripe-like, grid-like, or lattice-like arrangement structures can be generated. Furthermore, by applying frequency shift keying (FSK) or phase shift keying (PSK) to the signal, controllable oscillation of the nodes can be achieved, enabling functions such as mixing. By reducing the finger spacing of the interdigitated electrodes 40, the response frequency can be increased. Furthermore, by increasing the amplitude of the applied acoustic signal, a higher amplitude acoustic field can be generated at the center of the droplet above the second working electrode 232. A heating effect is generated in the droplet through the acoustic-thermal effect, and the temperature range can be controlled by controlling the amplitude.

[0033] In this embodiment, the focused sound field and thermal field module 43 consists of a set of concentric fan-shaped interdigitated electrodes 40, with their centers located on the third working electrode 233. This ensures that the sound waves can be precisely applied to the droplet above the third working electrode 233. The two pins of the set of concentric fan-shaped interdigitated electrodes 40 are respectively connected to two sound wave pin electrodes 3. By applying a sound wave signal, a focused sound field can be generated in the droplet on the third working electrode 233. Due to the sound energy gradient and energy dissipation, eddies are generated in the droplet. The intensity of the eddies can be controlled by controlling the amplitude, thereby achieving droplet mixing.

[0034] In this embodiment, the acoustic eddy current enrichment module 44 consists of two right-angled trapezoidal interdigitated electrodes 40. The right-angled side of the upper right-angled trapezoidal interdigitated electrode 40 is located at the upper end of the first working electrode 231, and the right-angled side of the lower right-angled trapezoidal interdigitated electrode 40 is located at the lower end of the first working electrode 231. The two right-angled trapezoidal interdigitated electrodes 40 have a rotationally symmetrical structure, with the center point of rotation being the center point of the first working electrode 231. The rotation angle is 180 degrees, that is, the upper right-angled trapezoidal interdigitated electrode 40 rotates 180° around the center point of the first working electrode 231 to form the lower right-angled trapezoidal interdigitated electrode 40. The two pins of each right-angled trapezoidal interdigitated electrode 40 are respectively connected to two acoustic wave pin electrodes 3. The positive and negative pins of the same right-angled trapezoidal interdigitated electrode 40 have different interdigital spacings, and the tilt angle of the right-angled trapezoidal interdigitated electrode 40 is determined by design requirements. By applying a sound wave signal, an acoustic flow can be generated in the droplet on the corresponding first working electrode 231. Since the sound field on both sides of the first working electrode 231 can form an asymmetric sound pressure gradient and a rapid decay of the acoustic flow, a directional vortex is formed. By designing a specific tilt angle and the width of the interdigitated electrode, the particles in the droplet can be enriched. The particle enrichment speed can be controlled by controlling the amplitude of the input signal.

[0035] In this embodiment, the dielectric layer 202 is SU-8 photoresist, the upper hydrophobic layer 103 and the lower hydrophobic layer 201 are both Teflon layers, the coating layer 102 is an ITO (indium tin oxide) layer, the substrate 204 is a lithium niobate (128° Y-cut or Z-cut) substrate 204, and the substrate 204 can adopt different tangentials according to different acoustic field design requirements; the glass layer 101 is a sodium calcium-based or silicon boron-based substrate.

[0036] This invention also provides a method for fabricating a digital acoustic fluid control chip, comprising the following steps: Preparation of upper electrode 100: Coating layer 102 and upper hydrophobic layer 103 are sequentially coated on the lower surface of glass layer 101; Preparation of lower electrode plate 200: 1) The corresponding chip sample is prepared on the substrate 204 by photolithography; 2) An electrode layer 203 is fabricated on a chip sample using a thin film deposition process. The electrode layer 203 includes multiple EWOD pin electrodes 1, multiple driving electrodes 2, multiple acoustic wave pin electrodes 3, and interdigital transducers 4. The interdigital transducers 4 include an acoustic field and electric field multiplexing module 41, an acoustic standing wave field and thermal field module 42, a focused acoustic field and thermal field module 43, and an acoustic eddy current enrichment module 44. Each driving electrode 2 is connected to one EWOD pin electrode 1. Both sides of the acoustic field and electric field multiplexing module 41, both sides of the acoustic standing wave field and thermal field module 42, both sides of the focused acoustic field and thermal field module 43, and both sides of the acoustic eddy current enrichment module 44 are connected to two acoustic wave pin electrodes 3. One side of the acoustic field and electric field multiplexing module 41 is also connected to one EWOD pin electrode 1. 3) Using a photoresist removal process, the chip sample is placed in acetone, anhydrous ethanol and deionized water respectively for ultrasonic treatment to remove the photoresist and obtain the patterned target chip. 4) A dielectric layer 202 is coated on the target chip, excluding the EWOD pin electrode 1 and the acoustic wave pin electrode 3, using photolithography. 5) Coat the area of ​​the dielectric layer 202 except for the EWOD pin electrode 1 and the acoustic wave pin electrode 3 with the lower hydrophobic layer 201; The upper electrode 100 and the lower electrode 200 are bonded together with spacer tape to form a complete digital acoustic flow control chip.

[0037] This invention also provides a multi-dimensional sample processing method for a digital acoustic flow control chip, comprising the following steps: The droplet sample is injected into the reservoir 21 using a syringe pump or pipette, and the gap between the upper electrode 100 and the lower electrode 200 is filled with silicone oil or air. The droplet sample is split into smaller droplets by driving electrode 2 and moved to the acoustic working area 23 via droplet transport area 22. Applying acoustic signals to different modules in the interdigital ring energyr 4 can achieve different functions. Specifically, the acoustic standing wave field and thermal field module 42 can be used to arrange, oscillate, and heat the particles in the droplet sample. The focused acoustic field and thermal field module 43 can be used to mix and heat the two droplet samples and accelerate the reaction of the droplet sample. The acoustic eddy current enrichment module 44 can be used to enrich the particles in the droplet sample. The acoustic field and electric field multiplexing module 41 can be used to move the droplet sample and mix and heat the particles in the droplet sample.

[0038] In this invention, such as Figure 6As shown, magnetic beads and microspheres are used to demonstrate the different functions of the acoustic working area 23. A droplet sample is injected between the upper electrode 100 and the lower electrode 200 using a syringe pump or pipette. The driving electrode 2 of the digital acoustic flow control chip splits the droplet sample carrying the magnetic beads or microspheres into smaller droplets and moves them to the acoustic working area 23. Turning off the driving electrode 2 and turning on the interdigital transducer 4 enables various functions of the digital acoustic flow control chip. Figure 6 (a) shows a physical image of the digital acoustic flow control chip. Figure 6 (b) is a microscopic image of the acoustic working area 23 under a 2x microscope.

[0039] In this invention, when the droplet sample moves to the first working electrode 231, the driving electrode 2 is turned off, the acoustic eddy current enrichment module 44 is turned on, and a sinusoidal signal with a frequency of 28MHz is applied. An asymmetric acoustic pressure gradient can be obtained on both sides of the first working electrode 231, and at the same time, the high-frequency acoustic current will rapidly attenuate in the droplet. The combination of the two can form a directional eddy current in the droplet, realizing the enrichment of particles in the droplet. Figure 6 As shown in (c), after the sound waves are turned on, it can be seen that the particles are concentrated in the center of the working area.

[0040] In this invention, when the droplet sample moves to the third working electrode 233, the driving electrode 2 is turned off, the focusing acoustic field and thermal field module 43 is turned on, and a sinusoidal signal with a frequency of 26.5MHz is applied. A focused acoustic field can be generated in the droplet above the third working electrode 233. Due to the acoustic energy gradient and energy dissipation, eddies are generated in the droplet. The intensity of the eddies can be controlled by controlling the amplitude, thereby achieving mixing between different droplet samples and accelerating the contact efficiency of different samples in the droplet, thus shortening the reaction time. Figure 6 As shown in (d), the particles can be observed to move rapidly along the acoustic vortex trajectory in the droplet.

[0041] In this invention, when the droplet sample moves to the second working electrode 232, the driving electrode 2 is turned off, and the acoustic standing wave field and thermal field module 42 is turned on. A sinusoidal signal with a frequency of 12MHz is applied, which can generate a standing wave field in the droplet. The particles in the standing wave field are subjected to acoustic radiation force and move towards the antinodes, generating a standing wave field within the droplet. Figure 6 (e) shows the lattice-like arrangement structure.

[0042] The above description is only a part of the embodiments of the present invention and does not limit the scope of protection of the present invention. Any equivalent device or equivalent process transformation made based on the content of the present invention specification and drawings, or direct or indirect application in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A digital acoustic flow chip, characterized in that, The bipolar plate structure comprises an upper bipolar plate and a lower bipolar plate, the upper bipolar plate comprises a glass layer, a coating layer and an upper hydrophobic layer arranged in sequence from top to bottom, and the lower bipolar plate comprises a lower hydrophobic layer, a medium layer, an electrode layer and a substrate arranged in sequence from top to bottom; The electrode layer comprises a plurality of EWOD pin electrodes, a plurality of driving electrodes, a plurality of acoustic wave pin electrodes and an interdigital transducer, the interdigital transducer comprises a sound field and electric field multiplexing module, a sound standing wave field and thermal field module, a focused sound field and thermal field module and a sound eddy current enrichment module; each driving electrode is connected with an EWOD pin electrode, the two sides of the sound field and electric field multiplexing module, the two sides of the sound standing wave field and thermal field module, the two sides of the focused sound field and thermal field module and the two sides of the sound eddy current enrichment module are connected with two acoustic wave pin electrodes, and one side of the sound field and electric field multiplexing module is also connected with an EWOD pin electrode.

2. A digital acoustic flow chip as claimed in claim 1, characterized in that The plurality of driving electrodes are distributed in a liquid storage area, a droplet transportation area and a sound wave working area, the liquid storage area, the droplet transportation area and the sound wave working area are located in a central region of the electrode layer, the liquid storage area is located at the upper end of the central region and is used for storing an initial droplet sample, the droplet transportation area is distributed between the liquid storage area and the sound wave working area, a part of the droplet transportation area is connected with the liquid storage area and is used for extracting droplets from the liquid storage area and into the droplet transportation area, another part of the droplet transportation area is connected with the sound wave working area and is used for transporting the droplets to the sound wave working area for processing, and the sound wave working area is located in a core functional region of the electrode layer and is close to the interdigital transducer; the driving electrodes in the liquid storage area, the droplet transportation area and the sound wave working area are connected with the EWOD pin electrodes.

3. A digital acoustic flow chip as claimed in claim 2, characterized in that The plurality of driving electrodes comprise a liquid storage electrode group distributed in the liquid storage area, a transportation electrode group distributed in the droplet transportation area and a working electrode group distributed in the sound wave working area, the liquid storage electrode group comprises a first liquid storage electrode, a second liquid storage electrode and a third liquid storage electrode, the transportation electrode group comprises a first longitudinal transportation part composed of two longitudinally connected transportation electrodes, a second longitudinal transportation part composed of two longitudinally connected transportation electrodes, a third longitudinal transportation part composed of two longitudinally connected transportation electrodes, a transverse transportation part composed of eight transversely connected transportation electrodes, a first connecting transportation part composed of one transportation electrode, a second connecting transportation part composed of one transportation electrode, a third connecting transportation part composed of one transportation electrode and a fourth connecting transportation part composed of one transportation electrode, and the working electrode group comprises a first working electrode, a second working electrode and a third working electrode. The first, second, and third liquid storage electrodes are located on the same horizontal line. The lower end of the first liquid storage electrode is connected to the upper end of the first longitudinal transport section, the lower end of the second liquid storage electrode is connected to the upper end of the second longitudinal transport section, and the lower end of the third liquid storage electrode is connected to the upper end of the third longitudinal transport section. The upper end of the leftmost transport electrode in the transverse transport section is connected to the lower end of the first longitudinal transport section, and the upper end of the rightmost transport electrode in the transverse transport section is connected to the lower end of the third longitudinal transport section, with its right end connected to the left end of the sound field and electric field multiplexing module. The upper end of the fourth transport electrode from left to right in the transverse transport section is connected to the lower end of the second longitudinal transport section. The right end of the first connecting transport section is connected to the transverse transport section. The left end of the leftmost transport electrode in the transport section, the upper end of the second connecting transport section is connected to the lower end of the fourth transport electrode from left to right in the transverse transport section, the upper end of the third connecting transport section is connected to the lower end of the rightmost transport electrode in the transverse transport section, and the left end of the fourth connecting transport section is connected to the right end of the sound field and electric field multiplexing module; the right end of the first working electrode is connected to the left end of the first connecting transport section, and its upper and lower ends are connected to the acoustic eddy current enrichment module; the upper end of the second working electrode is connected to the lower end of the second oblique transport section, and its left, right and lower ends are all connected to the acoustic standing wave field and thermal field module; the upper end of the third working electrode is connected to the lower end of the third oblique transport section, and its lower end is connected to the focusing sound field and thermal field module; Each electrode in the liquid storage electrode group, transport electrode group, and working electrode group is a square or rectangular structure, and the area of ​​a single electrode in the liquid storage electrode group is greater than the area of ​​a single electrode in the working electrode group and greater than the area of ​​a single electrode in the transport electrode group.

4. The digital acoustic flow chip of claim 1, wherein, The sound field and electric field multiplexing module is composed of a single interdigital electrode. The two pins of the interdigital electrode are respectively connected to two acoustic wave pin electrodes, and one of the pins of the interdigital electrode is also connected to an EWOD pin electrode.

5. A digital acoustic flow chip as claimed in claim 3, wherein, The acoustic standing wave field and thermal field module consists of three interdigitated electrodes arranged in a cross pattern, which are respectively arranged at the left, right and lower ends of the second working electrode. The two pins of each interdigitated electrode are respectively connected to two acoustic wave pin electrodes.

6. A digital acoustic flow chip as claimed in claim 3, characterized in that, The focused sound field and thermal field module consists of a set of concentric sector-shaped interdigital electrodes, with the center of the circle located on the third working electrode. The two pins of the set of concentric sector-shaped interdigital electrodes are respectively connected to two acoustic wave pin electrodes.

7. A digital acoustic flow chip as claimed in claim 1, wherein, The acoustic eddy current enrichment module consists of two right-angled trapezoidal interdigitated electrodes. The right-angled side of the upper right-angled trapezoidal interdigitated electrode is located at the upper end of the first working electrode, and the right-angled side of the lower right-angled trapezoidal interdigitated electrode is located at the lower end of the first working electrode. The two right-angled trapezoidal interdigitated electrodes have a rotationally symmetric structure, with the center point of rotation being the center point of the first working electrode. The rotation angle is 180 degrees, that is, the upper right-angled trapezoidal interdigitated electrode rotates 180° along the center point of the first working electrode to form the lower right-angled trapezoidal interdigitated electrode. The two pins of each right-angled trapezoidal interdigitated electrode are respectively connected to two acoustic wave pin electrodes.

8. The digital acoustic flow chip of claim 1, wherein, The dielectric layer is SU-8 photoresist, the upper and lower hydrophobic layers are both Teflon layers, the coating layer is an ITO layer, the substrate is a lithium niobate substrate, and the glass layer is a sodium-calcium-based or silicon-boron-based substrate.

9. A method for fabricating a digital acoustic fluid control chip, characterized in that, Includes the following steps: Upper electrode preparation: A coating layer and an upper hydrophobic layer are sequentially coated on the lower surface of the glass layer; Lower electrode preparation: 1) Fabricate corresponding chip samples on a substrate using photolithography; 2) An electrode layer is fabricated on a chip sample using a thin-film deposition process. The electrode layer includes multiple EWOD pin electrodes, multiple driving electrodes, multiple acoustic wave pin electrodes, and interdigital transducers. Each interdigital transducer includes an acoustic field and electric field multiplexing module, an acoustic standing wave field and thermal field module, a focused acoustic field and thermal field module, and an acoustic eddy current enrichment module. Each driving electrode is connected to one EWOD pin electrode. Both sides of the acoustic field and electric field multiplexing module, both sides of the acoustic standing wave field and thermal field module, both sides of the focused acoustic field and thermal field module, and both sides of the acoustic eddy current enrichment module are connected to two acoustic wave pin electrodes. One side of the acoustic field and electric field multiplexing module is also connected to one EWOD pin electrode. 3) Using a photoresist removal process, the chip sample is placed in acetone, anhydrous ethanol and deionized water respectively for ultrasonic treatment to remove the photoresist and obtain the patterned target chip. 4) Apply a dielectric layer to the area of ​​the target chip, excluding the EWOD pin electrode and the acoustic wave pin electrode, using photolithography. 5) Coat the area on the dielectric layer except for the EWOD pin electrode and the acoustic wave pin electrode with a hydrophobic layer; The upper and lower electrode plates are bonded together with spacer tape to form a complete digital acoustic fluid control chip.

10. A method for multi-dimensional sample processing of a digital acoustic flow chip, characterized in that Includes the following steps: Inject the droplet sample into the reservoir area and fill the gap between the upper and lower electrodes with silicone oil or air. The droplet sample is split into smaller droplets by driving electrodes and moved from the droplet transport region to the acoustic working region; An acoustic signal is applied to the acoustic working area. The arrangement, oscillation and heating of particles in the droplet sample are realized through the acoustic standing wave field and thermal field module. The mixing and heating of two droplet samples and the acceleration of the droplet sample reaction are realized through the focusing acoustic field and thermal field module. The particles in the droplet sample are enriched through the acoustic eddy current enrichment module. The movement of the droplet sample and the mixing and heating of particles in the droplet sample are realized through the acoustic field and electric field multiplexing module.

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