System for controlling deposition of fluid onto a substrate - Patents.com

Abstract

The present invention relates to a system (10) for controlled deposition of a fluid onto a substrate (20), and a method employing the system (10). The system: - a nanoinjector (100); a mechanical resonator (120) fixed to the nanoinjector (100) and adapted to detect contact between the nanoinjector (100) and the substrate (20); - control means (148) of the mechanical resonator (120), comprising: ■ excitation means (142) adapted to vibrate the mechanical resonator (120) at a vibration frequency (fi); ■ detector means (144) adapted to detect vibrations of the mechanical resonator (120); ■ Adjuster means (146) adapted to adjust the contact between the nanoinjector (100) and the substrate (20) by controlling the vibration of the mechanical resonator (120); a control means comprising: It is equipped with:

Description

[Technical field]

[0001] The present invention relates to a system for depositing fluids in such a way as to obtain nanometric layers.

[0002] More precisely, the invention relates to a system for controlling the deposition of a fluid on a substrate, a method for depositing a fluid on a substrate, the use of the system for additive manufacturing, and the products obtained by said method. [Background technology]

[0003] Additive manufacturing is a general term that encompasses a variety of techniques based on layer-by-layer deposition. Two main families of additive manufacturing are distinguished: direct printing techniques and the so-called indirect printing techniques. The former are those in which the desired material is deposited directly on the substrate. The indirect techniques are those in which an energy source, for example a laser or a UV lamp, is used to act on a bath of the desired material.

[0004] Additive manufacturing is growing rapidly and causing significant changes in how industry designs its manufacturing processes. Currently, several additive manufacturing techniques exist that make it possible to obtain objects with sizes ranging from 1 millimeter to 1 meter, with consideration being given to achieving sub-millimeter sizes.

[0005] A technique of indirect printing for depositing fluids known to those skilled in the art is two-photon polymerization, which allows printing objects with a laser on a photopolymerizable resin. The resin must be transparent to the wavelength of the laser in order to allow the chemical reaction and polymerization to occur. The resolution of this technique is half the wavelength of the laser, i.e. about 100 nanometers. This technique has the advantage that complex objects can be made very precisely, not least because of the precision of the laser movement. However, this technique is limited not only by the complexity of the equipment, but also by the constraints imposed on the materials used, which must be photopolymerizable.

[0006] Another indirect printing technique is the electron beam assisted deposition technique (FEBID), in which electrons bombard a precursor gas of the desired material to deposit it on a substrate. This technique can be implemented, for example, in a scanning electron microscope. FEBID allows a resolution of the order of one nanometer to be obtained by focusing an electron beam on a spot of very small size (less than 1 nm). Even though this technique is characterized by a possible non-uniform resolution and the possibility of manufacturing complex objects with in situ characterization, it has not yet been fully realized for high-precision deposition. In fact, the interaction between the electron beam and the volatile precursors is difficult to control, and deposits with sizes larger than the precision of the focus are often generated. It is also essential to find precursors suitable for the conditions of use of the equipment in which the deposition can be performed, which results in a significant reduction in the possibilities of manufacturing materials.

[0007] More recently, techniques using localized probe tips (AFM or STM) have made it possible to achieve resolutions approaching 100 nanometers, as shown, for example, in International Publication No. WO2017 / 106199 and U.S. Patent No. US2017 / 0259498.

[0008] All these latter techniques are direct printing techniques, using the translational precision and spatial resolution of localized probe techniques to deposit liquid materials onto a variety of substrates. These techniques allow the deposition of a wide variety of materials using a variety of solvents, such as: - various types of polymers; - Biological molecules (peptides, ADN, enzymes, etc.); - Various colloids. Summary of the Invention [Problem to be solved by the invention]

[0009] In one embodiment, the AFM tip is used like a quill pen. It is dipped into a drop of the material to be deposited before each deposition. In another embodiment, the tip is loaded with the small amount of liquid material required before deposition. However, even though the resolution is very high, these two approaches have a major drawback: continuous printing is not possible if there is no reservoir with a sufficient volume. Also, the precision of the resulting deposits is insufficient, since there are no parameters that allow to control the flow of material from or through the tip.

[0010] Thus, a need exists for additive manufacturing that features layers defined by thicknesses less than 100 nm, the ability to deposit a wide variety of materials, adjustable parameters that allow control of deposition, and a reservoir large enough to produce one or more objects without interruption. [Means for solving the problem]

[0011] To solve the above problems, in accordance with the present invention, a system for controlled deposition of a fluid onto a substrate comprises: - a nanoinjector comprising: ■ a reservoir for storing said fluid; a non-deformable projection having an exit orifice for withdrawing the fluid from the reservoir; A nanoinjector comprising: - a mechanical resonator fixed to the nanoinjector and adapted to detect contact between the protrusion and the substrate; - control means for said mechanical resonator, said control means comprising: - excitation means for said mechanical resonator adapted to vibrate said mechanical resonator at a vibration frequency (fi) so that said protrusion oscillates between a low position in which said protrusion is in contact with the substrate and a high position in which said protrusion is not in contact with the substrate; - detector means adapted to detect said vibrations of said mechanical resonator, and - adjuster means adapted to adjust the contact between the protrusions and the substrate by controlling the vibration of the mechanical resonator, said adjuster means being connected to a first adjustment displacement means adapted to move at least the substrate of the nanoinjector one towards the other or one away from the other along the axis z; A control means connected to the Equipped with:

[0012] In the context of the present invention, a fluid means a liquid or gel that can flow under stress values ​​greater than its threshold stress, with or without chemical species in suspension. For example, the fluid may be water, saline solution, vegetable oil, silicone oil, photolithography resins (SU8, etc.), ionic liquids, DNA-RNA strands, nanoparticles (colloids and others) of noble metals such as gold and silver, various biomaterials such as collagen, polysaccharides, proteins, ceramic materials such as zirconia, alumina, aluminum hydroxide, titanium dioxide, provided that the size of the particles is such that the fluid can pass through the exit orifice of the nanoinjector. For example, the exit orifice may be 7 to 10 times the diameter of the particles contained in the fluid to be deposited.

[0013] For example, the species in suspension may be colloidal species, polymeric species in solution, and the like.

[0014] In the context of the present invention, a substrate means a support which may be flat, structured or have a radius of curvature.

[0015] For example, structured supports can include supports having square shapes, hemispherical shapes, curved shapes, sawtooth shapes, pointed shapes, and the like.

[0016] In the context of the present invention, a nanoinjector means an injector with an ejection orifice having a diameter of less than 1 μm.

[0017] In the context of the present invention, an ejection orifice means an orifice through which a fluid from a nanoinjector is ejected and subsequently deposited on a substrate, the inner and outer diameters of which are adapted to the deposit that it is desired to obtain.

[0018] It should be noted that in addition to the inner diameter of the exit orifice, the outer diameter also influences the deposition. In fact, the outer diameter of the exit orifice influences the fluid meniscus formed between the protrusion and the substrate when the protrusion is brought into contact with the substrate. The ratio of the inner diameter to the outer diameter of the exit orifice is preferably in the range of 0.8 to 1. If a meniscus is formed by contact of the protrusion, in particular the wall located between the inner diameter and the outer diameter of the exit orifice, with the substrate, the deposition of the fluid on the substrate is ensured. Furthermore, if the ratio of the inner diameter to the outer diameter of the exit orifice is in the range of 0.8 to 1, the meniscus is more stable, ensuring deposition between the low and high positions of the protrusion. The deposition and stability are favored if the ratio of the inner diameter to the outer diameter of the exit orifice is close to 1, i.e. if the wall located between the inner diameter and the outer diameter of the exit orifice has the smallest possible thickness.

[0019] It should be noted that this design is directed to variable sized exit orifices. Also, the exit orifice may have any shape cross section, e.g. square, rectangular, elliptical, circular, etc. For example, the protrusion and nanoinjector may be one piece, the protrusion may form an integral part with the nanoinjector and therefore may be one piece with the reservoir, e.g. conical. In this case, there may be a nanocapillary with a conical shaped end, through which it is desired to deposit the fluid through the exit orifice. It should be noted that the shape does not have to be conical, but may feature an exit orifice of a given shape, e.g. with a desired exit orifice diameter that can be adjusted depending on the design parameters.

[0020] It should be noted that the reservoir may have a longitudinal shape, for example a cylindrical shape, with openings at both ends, i.e. a first opening directly or indirectly connected to the protrusion, and a second opening capable of supplying the reservoir.

[0021] It should further be noted that the nanoinjector reservoir and protrusion are not necessarily one piece, but may be separated or removable to allow replacement of the nanoinjector protrusion or reservoir, and that the mechanical resonator, control means, excitation means, detector means, and regulator means may each be individually replaceable.

[0022] Furthermore, the protrusions may preferably be functionalized.

[0023] In the context of the present invention, functionalized protrusions are meant protrusions with an exit orifice, the initial geometry of which, depending on the geometry of the protrusion, is modified by the addition of components in the protrusion. It is therefore possible to adjust the inner and / or outer diameter of the exit orifice of the protrusion by adding components in the protrusion, allowing the geometry of the exit orifice to be modified according to the desired application, the functionalization being performed before the operation of the system begins. For example, different functionalized protrusions may be obtained by inserting a nanotube into the protrusion so as to define the exit orifice and leaving one end of the nanotube protruding at the surface of the protrusion, the nanotube being fixed to the protrusion, for example with an adhesive. The nanotubes may have different diameters and may be made of carbon, boron nitride, molybdenum disulfide, silicon. For example, the nanotubes may have a length between 1 μm and 2 μm, an outer diameter between 60 nm and 200 nm, and an inner diameter between 5 nm and 50 nm. Another example of a functionalized protrusion may be a protrusion covered with a noble material, such as gold, that protects the fluid from UV radiation.

[0024] The exit orifice may preferably have an inner diameter of between 5 nm and 300 nm.

[0025] In the context of the present invention, non-deformable protrusions mean protrusions that have stable dimensions under the conditions of use of the system during deposition.

[0026] In the context of the present invention, the mechanical resonator fixed to the nanoinjector means a mechanical resonator that is in contact with the nanoinjector so that the vibration of the mechanical resonator is transmitted to the nanoinjector.

[0027] In the context of the present invention, control means means adapted, on the one hand, to measure the vibration difference between the vibration of the mechanical resonator and a set-point vibration transmitted to the mechanical resonator by the excitation means, and, on the other hand, to measure the vibration variations caused by contact between the protrusion and the substrate.

[0028] For example, the oscilloscope may have, or may not have, a proportional compensator (commonly referred to as a P compensator), an integral proportional compensator (commonly referred to as a PI compensator), or a proportional integral derivative compensator (commonly referred to as a PID compensator) as a control means to improve the servo control function and vibrate the mechanical resonator according to a set point vibration.

[0029] For example, the excitation means may include a piezoelectric, magnetic or even acoustic exciter, such as a speaker.

[0030] For example, the detector means may include electromechanical microsystems such as accelerometers, optical fibres or even devices comprising lasers.

[0031] The detector means preferably comprises: 5 The detector means may have a stiffness of less than N / m, which is a function of the material that the nanoinjector is made of.

[0032] The material from which the nanoinjector is constructed must be resistant to the fluids to be deposited. For example, if it is desired to deposit fluids containing strong acids such as hydrochloric acid, sulfuric acid, hydrofluoric acid, nitric acid, phosphoric acid, etc., onto substrates containing gallium arsenide, silicon dioxide, alumina, zirconia, boron nitride, the nanoinjector may be constructed from plastic materials such as high density polyethylene, polypropylene, polyvinyl chloride, polyvinylidene fluoride, or even polyether ketone.

[0033] In the context of the present invention, regulator means adapted to control contact between the protrusions and the substrate means means adapted to control the force of interaction of the substrate with the protrusions when there is contact between the protrusions and the substrate.

[0034] For example, the regulator means may include a proportional compensator (commonly referred to as a P compensator), an integral proportional compensator (commonly referred to as a PI compensator), or a proportional integral derivative compensator (commonly referred to as a PID compensator).

[0035] In the context of the present invention, a first displacement means adapted to move at least the substrate closer to or away from the nanoinjector means a means adapted to move the substrate along the axis z closer to or away from the nanoinjector in such a way as to control the contact between the substrate and the protrusions.

[0036] The first displacement means may be connected to second displacement means adapted to displace the substrate along axes x, y orthogonal to axis z to produce a pattern, the three orthogonal axes x, y, z forming a direct trihedron, such that the first displacement means allows adjusting the contact between the projections and the substrate and the second displacement means allows producing a predetermined pattern.

[0037] The first displacement means and the second displacement means are preferably contained within a single displacement system.

[0038] The first displacement means and / or the second displacement means preferably comprise piezoelectric motors with sub-nanometer resolution.

[0039] The reservoir may preferably be connected to an external reservoir, thus allowing the volume of fluid deposited to be regulated.

[0040] Another object of the present invention is to provide a method for depositing a fluid on a substrate, comprising the steps of: a) procuring a system as defined above; b) initiating a controlled vibration of the protrusion by exciting the mechanical resonator by means of the excitation means which initiates vibration of the mechanical resonator at a vibration frequency, the vibration of the mechanical resonator being transmitted to the protrusion; c) using the first displacement means to move the substrate closer to the protrusions to create dynamic contact between the substrate and the protrusions, the protrusions oscillating between a low position in which the protrusions are in contact with the substrate and a high position in which the protrusions are not in contact with the substrate; d) detecting the vibration of the mechanical resonator by the detector means to observe a variation in vibration upon contact between the protrusion and the substrate; e) adjusting the dynamic contact between the protrusions and the substrate using said adjuster means and in response to vibrational variations to form a fluid meniscus between the protrusions and the substrate; f) depositing fluid through the ejection orifice onto the substrate while the protrusions are in contact with the substrate; Includes.

[0041] It should be noted that the system may also function in a configuration in which the nanoinjector is positioned vertically, i.e., when the tilt angle between the surface on which it is desired to deposit fluid and the direction in which the nanoinjector is positioned is close to 90°.

[0042] It should be noted that according to the method of the present invention, it is possible to carry out at least two of steps b), d), e) and f) simultaneously.

[0043] It should be noted that the deposition may be continuous or discontinuous, the latter may or may not follow a predetermined pattern which may or may not be repeatable.

[0044] In the context of the present invention, dynamic contact means discontinuous or intermittent contact at the frequency of vibration of the mechanical resonator.

[0045] It should be noted that using a nanoinjector with an exit orifice smaller than 1 μm, it is possible to obtain deposits having thicknesses in the range of 1% to 150% of the diameter of the exit orifice.

[0046] In the context of the present invention, control by a control means of a mechanical resonator means control of at least the vibration frequency, and possibly also of additional parameters related to the vibration, such as frequency, amplitude phase, or even consisting of an analysis of the excitation of the vibration.

[0047] The distance between the low point and the high point may preferably be between 1 nm and 1 μm.

[0048] The system may preferably further comprise the step g) of sweeping the nanoinjector over the substrate following a trajectory that can be modified in real time to produce the first layer.

[0049] Note that the trajectory may be predetermined to produce a desired pattern or to be followed in any direction.

[0050] Also, note that the first layer can be continuous or discontinuous.

[0051] The sweeping step g) may preferably be carried out under conditions of constant and predetermined contact between the projections and the substrate.

[0052] The system may preferably further comprise a step of solidifying the first layer. This solidification step allows for the application of a dissolution and / or decomposition potential during the production of the second layer on the first layer. This solidification step may be a subsequent step or may be performed in real time during deposition. It is noted that this step is optional, since the deposition of the essentially hard fluid may only be performed upon removal of the deposit from the nanoinjector.

[0053] It should be noted that the performance of the solidification step depends on the properties of the fluid being deposited.

[0054] The step g) of sweeping the nanoinjector may preferably be performed at a speed of less than 40 μm / s.

[0055] It should be noted that it is possible, for example, to slow down the sweep rate and / or to reduce the amplitude of the oscillations to favor controllability of the deposition.Furthermore, fluids containing species in solution that are small, i.e., have a particle size range less than 10 times the amplitude of the oscillations and less than 10 times the desired thickness of the deposit, may equally be used.

[0056] The system preferably performs, after performing step g) of sweeping the nanoinjector, the following: h) controlling at least the contact between the protrusion and the first layer and the vibration frequency by the control means of the mechanical resonator; i) depositing a second layer over the first layer; j) repeating the previous steps h) and i) until the desired thickness is obtained; It may further include.

[0057] The control step h) allows for self-contact between the protrusion and the first layer in order to prevent degradation of the first layer.

[0058] Another object of the invention relates to the use of the system defined above for additive manufacturing.

[0059] Another object of the invention relates to a product obtained by the method defined above, which product comprises one or more uniform and stable layers having shapes defined by lengths of 1 μm or more.

[0060] However, particularly when using an external reservoir connected to the nanoinjector reservoir, there may be deposition layers having lengths much larger than 1 μm, for example several kilometers.

[0061] It is noted that the minimum width of the deposited layer is the outer diameter of the protrusion and may therefore be, for example, between 0.5 nm and 100 μm, preferably between 5 nm and 300 nm. It is further noted that the height of the deposited layer decreases as the viscosity of the fluid decreases, decreases as the sweep speed of the nanoinjector decreases, increases as the amplitude of the vibration increases, and increases as the inner diameter of the protrusion increases.

[0062] For example, the maximum ratio between the thickness and width of the first layer may be approximately equal to 0.4.

[0063] The resulting product may preferably include multiple superimposed layers.

[0064] It should be noted that for the stability of the meniscus between the high and low positions, it may be advantageous to, for example, reduce the viscosity of the fluid, increase the permeability of the protrusion, i.e., increase the volume of fluid that will flow through the protrusion for a given forcing force between the reservoir and the meniscus, increase the internal cross-section of the protrusion, increase the affinity of the fluid with the material of the substrate and with the external material of the protrusion, use a resonator with a low resonant frequency to reduce the vibration frequency of the protrusion and to detectably reduce the amplitude of the vibration.

[0065] In the context of the present invention, a given forcing force means the application of a controlled pressure to the fluid in the reservoir. For example, this forcing force may be performed using compressed air, mechanically using a piston / cylinder system, or even electrically by applying a voltage between the substrate and the nanoinjector.

[0066] Thus, using the present invention to print in a localized manner, it is possible to create nanometer or micrometer circuit connections.

[0067] The invention will be better understood on reading the following description, given by way of example only, and with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0068] [Figure 1] FIG. 1 illustrates a system in accordance with a preferred embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating the steps that may be performed to function a system according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0069] FIG. 1 shows a system 10 for controlled deposition of a fluid onto a substrate 20 .

[0070] For example, the fluid may be any type of fluid, such as a SU8 2002 solution, a SU8 2010 solution, an ionic liquid, a gel, or even a paste.

[0071] The substrate used here is a flat substrate having a roughness of less than 1 nanometer.

[0072] The system of FIG. 1 comprises a nanoinjector 100 having a reservoir 102 for storing a fluid and a non-deformable protrusion 104 having an ejection orifice 108 that draws the fluid from the reservoir 102 .

[0073] For example, the reservoir 102 and nanometer-sized nanoinjector 100 may be fabricated by laser pulling a cylindrical glass capillary tube with a length approximately equal to 2 cm and a conical thread with a length of 2 mm using a Sutter Instruments P-2000 laser puller. The internal diameter of the capillary tube after laser irradiation varies from 0.5 mm to tens of nanometers at the apex. In this configuration, the nanoinjector 100 features a reservoir tube for fluid. The tube has a conical end into which a nanotube is inserted that features an exit orifice 108 that functions as a protrusion 104. The tube may be made of glass and may have an internal diameter approximately equal to 20 nm. The nanotube may be a carbon nanotube with a length of about 1 μm, an external diameter approximately equal to 20 nm, and an internal diameter approximately equal to 1 nm.

[0074] It should be noted that to increase the available volume of fluid to be deposited, reservoir 102 may be connected to an external reservoir (not shown in FIG. 1).

[0075] The system 10 further comprises a mechanical resonator 120 affixed to the nanoinjector 100 .

[0076] The mechanical resonator 120 may take the form of a tuning fork, the body of which is screwed at its base by a system of micrometer screws to a block movable along three axes in space. In this configuration, the nanoinjector 100 is attached to the handle of the tuning fork, for example by means of glue, with the ejection orifice 108 facing downwards towards the substrate 20, which is positioned on the piezoelectric scanner. The body of the nanoinjector 100, used as the reservoir 102, is filled with the fluid to be deposited using a micrometer syringe, which also fills the threads by capillary action. For example, the tuning fork may comprise a branch, which may be made of aluminum and have a diameter approximately equal to 1 cm and a length approximately equal to 10 cm. The nanoinjector 100 may then be fixed to the free end of the tuning fork. The tuning fork is designed to reproduce the same geometry, the same dimensional ratios of the various components that make up the quartz tuning fork commonly used in AFMs.

[0077] It should be noted that the mechanical resonator 120 preferably has a high enough quality factor to allow tuning of the contact with the desired frequency shift. For example, a mechanical resonator 120 with a quality factor on the order of 10,000 may be used, with a resonant frequency to quality factor ratio between 0.1 and 20.

[0078] The system 10 further comprises a control means 148 for the mechanical resonator 120. The control means 148 allows for the control of the deposition of the fluid onto the substrate 20.

[0079] The control means 148, which in this embodiment is an oscillator with a first PID compensator 1, is in particular connected to an excitation means 142, which excites the mechanical resonator 120 to vibrate it at a vibration frequency fi, so that the protrusion 104 vibrates between a low position where the protrusion 104 is in contact with the substrate 20 and a high position where the protrusion 104 is not in contact with the substrate 20. The excitation means 142 in this embodiment is a piezoelectric exciter, which is attached to the mechanical resonator 120.

[0080] The distance between the low and high positions depends on all the characteristics of the system, such as the nature of the protrusions, the fluid to be deposited, the vibration frequency, the nature of the substrate 20, or even the speed of movement of the substrate 20.

[0081] The control means 148 is further connected to the detector means 144, which is adapted to detect vibrations of the mechanical resonator 120 and read the response of the mechanical resonator 120 to excitation by the excitation means 142. In this embodiment, the detector means 144 is an accelerometer that is also attached to the mechanical resonator 120.

[0082] The control means 148 is further connected to the adjuster means 146 , which is adapted to adjust the contact between the protrusions 104 and the substrate 20 by controlling the vibration of the mechanical resonator 120 .

[0083] The regulator means 146 is a second PID compensator 2, to which the compensator is connected, allowing the adjustment of the contact using a first displacement means 160 adapted to move the substrate 20 and the nanoinjector 100 closer or further away along the axis z. The first displacement means 160 is further connected to a second displacement means adapted to move the substrate 20 along the axes x and y, the three axes x, y and z being orthogonal and forming a direct trihedron, so as to be able to generate any atom on the surface of the substrate. To ensure high precision, the first displacement means 160 and / or the second displacement means comprise piezoelectric motors with a sub-nanometer resolution. In particular, the first displacement means 160 and the second displacement means may be part of a single displacement system. The single displacement system may for example be a piezoelectric scanner on which the substrate 20 rests. The latter has a maximum displacement approximately equal to 50 μm.

[0084] Additionally, a video camera focused on the exit orifice 108 may also be used to observe the nanoinjector 100 and substrate 20 as they move closer to one another.

[0085] It should be noted that in this embodiment the substrate tilt angle between the plane of motion of the piezoelectric scanner and the substrate plane is less than 5°.

[0086] A method of using the system shown in FIG. 1 to deposit a fluid onto a substrate 20 is now described with reference to FIG.

[0087] In a preliminary and optional step, step 1 of FIG. 2, the protrusion 104 is brought close to the substrate 20 by a distance of less than 50 μm, corresponding to the maximum travel of the piezoelectric scanner, using a video camera focused on the exit orifice 108 using the micrometer screw of a tuning fork, a mechanical resonator 120, allowing the piezoelectric scanner to continue to bring the two components closer to each other.

[0088] In the next step, step 2 in FIG. 2, the protrusion 104 starts to vibrate in a controlled manner by excitation of the tuning fork by a piezoelectric exciter, causing the tuning fork to vibrate at a vibration frequency fi. In this way, the vibration of the tuning fork is transmitted to the protrusion 104.

[0089] Therefore, in another step, step 3' in [Fig. 2], it is possible to measure the resonance of the system consisting of the tuning fork, the piezoelectric exciter and the accelerometer, so as to determine the frequency of the resonance of the tuning fork and its quality factor. The tuning fork is mechanically excited by the piezoelectric exciter at its resonance in its natural vibration with frequency f0. This vibration is detected by the accelerometer, which has a resonance sensitivity of up to 0.5 nm amplitude, which in this case corresponds to the minimum amplitude of vibration when the system is functional, i.e. the minimum distance between the high and low positions.

[0090] For example, the piezoelectric exciter may be fed with an electrical signal whose frequency corresponds to its mechanical excitation frequency. The frequency of this electrical signal is adjusted by a first PID compensator 1 to control the vibration of the tuning fork so that the response of the tuning fork detected by the accelerometer is in phase with the signal from the piezoelectric exciter, and the tuning fork vibrates according to the vibration of the piezoelectric exciter. The set point of this feedback loop is therefore for the phase difference between the vibration of the piezoelectric exciter and the vibration of the tuning fork to be zero. At this time, the tuning fork is in phase with the piezoelectric exciter. The tuning fork is therefore excited at a resonant frequency, which depends on its mechanical properties as well as on its interaction with the environment.

[0091] In another step, step 3 of FIG. 2, which may be performed simultaneously with step 3′, a phase shift of the set point oscillation of the second PID compensator 2 can be predetermined, which corresponds to a phase shift induced by a given contact between the protrusion and the substrate 20. For example, this phase shift may be 10 mHz.

[0092] Then, in another step, step 4 of FIG. 2, a piezoelectric scanner is used to bring the substrate 20 closer to the protrusions 104, creating dynamic contact between the substrate 20 and the protrusions 104. Thus, the protrusions 104 oscillate between a low position, where the protrusions are in contact with the substrate 20, and a high position, where they are not in contact with the substrate 20.

[0093] It should be noted that meanwhile, the vibration of the tuning fork is detected by an accelerometer to observe the vibration fluctuations upon contact between the protrusions 104 and the substrate 20 .

[0094] Thus, upon contact between the protrusions 104 and the substrate 20, the force applied to the tuning fork / nanoinjector 100 assembly is modified. This modification modifies the resonant frequency and therefore the excitation frequency of the piezoelectric exciter, which is maintained at the resonant frequency of the tuning fork. For example, dynamic contact is determined to be achieved when the resonant frequency of the tuning fork / nanoinjector 100 assembly is modified by 10 mHz relative to the excitation frequency of the piezoelectric exciter, as selected in step 3. Thus, before proceeding to the subsequent steps, it can be verified that the system is not subject to a drift in resonant frequency over time.

[0095] Then, in step 5 of FIG. 2, the dynamic contact between the protrusion 104 and the substrate 20 is adjusted using the second PID compensator 2 in response to the vibration fluctuations, so as to form a meniscus of fluid between the protrusion 104 and the substrate 20. The substrate 20 is placed below the nanoinjector 100 on a three-axis piezoelectric scanner (for example, the piezoelectric scanner used may be Tritor101, Piezosystemjena) with a sub-nanometer resolution of movement. The second PID compensator 2 controls by a feedback loop the fine approach between the substrate 20 placed on the piezoelectric scanner and the nanoinjector 100 until contact between the protrusion 104 and the substrate 20 is achieved, towards a set-point phase shift of the previously selected 10 mHz resonant frequency. The stiffness of the tuning fork allows for a controlled approach and also prevents the sudden jump effect of the protrusion 104 in contact with the substrate 20 due to the meniscus between the protrusion 104 and the substrate 20.

[0096] In another step, the fluid is deposited onto the substrate 20 through the ejection orifices 108 during contact between the protrusions 104 and the substrate 20 .

[0097] Then, in a subsequent step, step 6 of FIG. 2, the nanoinjector 100 is swept over the substrate 20 along a trajectory that can be modified in real time by moving the substrate 20 relative to the nanoinjector 100 to produce a first layer.

[0098] The deposition design is generated by moving the substrate 20 while keeping the interaction with the nanoinjector constant thanks to the second PID corrector 2, which in step 5' of [Fig. 2] adjusts and controls the contact between the protrusions 104 and the substrate 20. Real-time detection of the interaction between the nanoinjector 100 and the surface of the substrate 20 makes it possible to prevent uncontrolled damage to the substrate 20 and the nanoinjector 100.

[0099] A set point, for example of the order of 10 mHz, may be maintained for the second PID compensator 2, but may be increased to several Hz if the protrusions 104 are tolerant of this type of force of intermittent contact with the substrate 20. The trajectory of the protrusions 104 is defined relative to the substrate 20 by the electronic control of the piezoelectric scanner connected to the second PID compensator 2. Also the speed at which it moves on this trajectory is defined. A sweep is then performed, maintaining a constant and defined contact between the protrusions 104 and the substrate 20. The piezoelectric scanner then follows the set trajectory, using the second PID compensator 2 and the piezoelectric scanner, at a set point speed of less than 40 μm / s and while maintaining a frequency shift of 10 mHz. The critical speed condition that must not be exceeded is the stability of the meniscus while oscillating between the low and high positions.

[0100] In another step, step 7' or 8 in FIG. 2, it is possible to solidify the first layer. For example, if a polymerizable ink is deposited, one may choose to expose the resulting first layer to UV light before proceeding to deposit a second layer thereon. This solidification step may be performed simultaneously with the deposition or afterwards.

[0101] Once deposition is complete, in another step, step 7 of FIG. 2, a piezoelectric scanner may be used to move the substrate 20 either away or in away from the nanoinjector 100, breaking contact between the two.

[0102] Then, in step 9 of [Figure 2], the micrometric screw of the tuning fork may be used to roughly move the protrusion 104 away from the substrate 20, and then the substrate 20 with the first layer deposited thereon may be pulled out.

[0103] With this kind of system and using this kind of method: - Volume 10mm 3 The reservoir (cross section is about 0.5 mm 2 a nanoinjector having a cylindrical reservoir with a diameter of approximately 1.0 mm and a length of approximately 2 cm, containing a SU8 2002 solution as a fluid, the nanoinjector having a protrusion functionalized by the insertion of a carbon nanotube having an inner diameter approximately equal to 50 nm and an injection orifice with an outer diameter approximately equal to 180 nm; - Quality factor is about 1.4.10 4 a tuning fork vibrating at a frequency approximately equal to 1.5 kHz to vibrate the protrusions between high and low positions, each position being spaced apart by a distance of less than 10 nm; a silicon substrate; - a substrate travel speed approximately equal to 0.125 μm / s; By employing this technique, regular and stable layers are obtained with a thickness approximately equal to 30 nm and a width approximately equal to 150 nm over a length of several micrometers.

[0104] Under the same conditions as before, with a substrate movement speed approximately equal to 0.5 μm / s, a regular and stable ink layer with a thickness approximately equal to 5 nm and a width approximately equal to 150 nm is obtained.

[0105] Under the same conditions as above, using a nanoinjector having a protrusion functionalized by inserting a carbon nanotube having an inner diameter approximately equal to 1 nm and an ejection orifice having an outer diameter approximately equal to 20 nm, a regular and stable layer of ink is obtained having a thickness approximately equal to 700 pm and a width approximately equal to 20 nm over a length of several micrometers.

[0106] In another example: - 3mm volume containing SU8 2010 solution 3 a nanocapillary as a nanoinjector, having a reservoir of 0.1 μm, no functionalized protrusions, but an ejection orifice with an inner diameter approximately equal to 200 nm; - Quality factor is 1.4.10 4 a tuning fork vibrating at a frequency of about 1.5 kHz, causing the protrusions to vibrate between high and low positions, each position being spaced apart by a distance of about 1 nm; a silicon substrate; - a substrate movement speed of less than 40 μm / s; Using this, a regular and stable layer of ink is obtained over a length of several micrometers, approximately 100 μm, with a thickness approximately equal to 35 nm and a width approximately equal to 200 nm.

[0107] Further examples include: - 10mm containing an ionic solution as the fluid (for example, known as Bmim PF6) 3 a nanoinjector comprising a reservoir of a volume of about 1000 nm, the nanoinjector having a protrusion functionalized by the insertion of a carbon nanotube having an inner diameter of about 60 nm and an exit orifice of about 5 nm in outer diameter, - Quality factor is 1.4.10 4 a tuning fork vibrating at a frequency of approximately 1.5 kHz approximately equally to cause the protrusions to vibrate between high and low positions, each position being spaced apart by a distance of less than 50 nm; a silicon substrate; - a substrate movement speed between 1 μm / s and 4 μm / s, Using this method, a regular and stable ink layer with a thickness approximately equal to 0.5 nm and a width approximately equal to 20 nm is obtained.

[0108] Using this type of predefined trajectory, complex shapes such as sinusoids, spirals, circles, etc. can be produced.

[0109] Additive manufacturing may be used to produce three-dimensional objects on demand. In fact, layers may be stacked one on top of the other, and the first layer may be pre-solidified by using any solidification process immediately after the deposition of the second layer. For example, about ten layers, each having a thickness approximately equal to 100 nm, may be stacked in sequence to produce a circular stack with a total thickness equal to a height of 1.5 μm and a diameter equal to 8 μm.

[0110] The two layers may also be crossed to form a cross, with the intersection having a thickness of 300 nm, which is equivalent to twice 150 nm, which may be the thickness of a single layer, with each layer having a thickness approximately equal to 100 nm.

[0111] The present invention has been shown and described in detail in the above description and drawings. The above is to be considered as illustrative and given by way of example, and not as limiting the invention to this single description. Numerous variations of the embodiments are possible.

Claims

1. A nanoinjector (100) comprising: a reservoir (102) for storing fluid; a nanoinjector (100) comprising a non-deformable protrusion (104) having an ejection orifice (108) for extracting said fluid from said reservoir (102); a mechanical resonator (120) fixed to said nanoinjector (100) and adapted to detect contact between said protrusions (104) and a substrate (20); - control means (148) of said mechanical resonator (120), comprising: - excitation means (142) of said mechanical resonator (120) adapted to vibrate said mechanical resonator (120) at a vibration frequency (fi) so that said protrusions (104) oscillate between a low position in which said protrusions (104) are in contact with said substrate (20) and a high position in which said protrusions (104) are not in contact with said substrate (20); - detector means (144) adapted to detect said vibrations of said mechanical resonator (120), said detector means (144) being an accelerometer attached to said mechanical resonator (120) and independent of said nanoinjector (100); - regulator means (146) adapted to regulate the contact between the protrusion (104) and the substrate (20) by controlling the vibration of the mechanical resonator (120), said regulator means (146) being connected to at least first regulating displacement means (160) adapted to move the nanoinjector (100) and the substrate (20) towards or away from each other along the axis z; a control means (148) connected to the A system (10) for controlling deposition of a fluid onto a substrate (20) for additive manufacturing, comprising:

2. The deposition control system of claim 1 , wherein the protrusions (104) are functionalized.

3. The deposition control system of claim 1 or 2, wherein the exit orifice (108) has an inner diameter of at least 5 nm and at most 300 nm.

4. 4. The deposition control system of claim 1, wherein the first displacement means (160) is connected to a second displacement means adapted to displace the substrate (20) along axes x, y orthogonal to the axis z to produce a pattern, the three axes x, y, z being mutually orthogonal.

5. The deposition control system of claim 4, wherein the first displacement means (160) and the second displacement means are part of a single displacement system.

6. The deposition control system of claim 4 or 5, wherein the first displacement means (160) and / or the second displacement means comprise a piezoelectric motor.

7. The deposition control system of claim 1 , wherein the reservoir (102) is connected to an external reservoir.

8. below: a) providing a system (10) according to any one of claims 1 to 7; b) initiating a controlled vibration of the protrusion (104) by exciting the mechanical resonator (120) by the excitation means (142) which initiates a vibration of the mechanical resonator (120) at a vibration frequency (f i ), the vibration of the mechanical resonator (120) being transmitted to the protrusion (104); c) using the first displacement means (160) to move the substrate (20) closer to the protrusions (104) to create dynamic contact between the substrate (20) and the protrusions (104), whereby the protrusions (104) oscillate between a low position where the protrusions (104) are in contact with the substrate (20) and a high position where the protrusions (104) are not in contact with the substrate (20); d) detecting the vibration of the mechanical resonator (120) by the detector means (144) to observe the variation of the vibration upon contact between the protrusion (104) and the substrate (20); e) using said adjuster means (146) and in response to said variation in vibration, adjusting the dynamic contact between said protrusions (104) and said substrate (20) to form a fluid meniscus between said protrusions (104) and said substrate (20); f) depositing fluid through said ejection orifices (108) onto said substrate (20) during contact between said protrusions (104) and said substrate (20); A method of depositing a fluid onto a substrate, comprising:

9. g) depositing a fluid by sweeping the nanoinjector (100) along a trajectory over the substrate (20) to produce a first layer; The fluid deposition method of claim 8 , wherein the trajectory is modifiable during step g).

10. The fluid deposition method of claim 9, wherein the sweeping step g) is performed while maintaining the constant and predetermined contact between the protrusions (104) and the substrate (20).

11. 11. The fluid deposition method of claim 9 or 10, further comprising solidifying the first layer.

12. A fluid deposition method according to any one of claims 9 to 11, wherein the step g) of sweeping the nanoinjector (100) is performed at a speed of less than 40 μm / s.

13. h) controlling at least the contact between the protrusion (104) and the first layer and the vibration frequency (fi) by means of the control means (148) of the mechanical resonator (120); i) depositing a second layer over the first layer; j) repeating the previous steps h) and i) until the desired thickness is obtained; The deposition method of claim 9 , further comprising:

14. A fluid deposition method according to any one of claims 8 to 13, wherein the distance between the low point and the high point is ≥ 1 nm and ≤ 1 µm.

15. 15. An article obtained by the fluid deposition process of any one of claims 8 to 14, comprising one or more layers having a length of 1 μm or greater.

16. 16. The article of manufacture of claim 15 comprising a plurality of superimposed layers.

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