Anesthesia bomb combined with micro-needle and micro-fluidic chip

Abstract

The invention belongs to the technical field of anesthesia tools, and discloses an anesthesia bomb combining a microneedle and a micro-fluidic chip, which is characterized in that an empennage assembly is automatically unfolded after being launched to form a stable airfoil profile, and the flight accuracy is guaranteed; and the piezoelectric control system impacts signal energy supply and is matched with a mechanical switch to realize accurate triggering after hit. Meanwhile, the fixing structure ensures that all parts are stable and free of displacement in the launching and flying process through a support, a limiting ring and a guide sleeve, a micro-fluidic chip is adopted for regulating and controlling liquid medicine conveying, a micro-needle array containing a pressure sensor is matched, medicine is released only when the micro-needle array pierces the tissue to reach a pressure threshold value, and waste and mistaken release of the liquid medicine are avoided. The effects of stable flying, accurate triggering and controllable liquid medicine conveying of the anesthesia bomb are achieved, the anesthesia efficiency and safety are improved, the anesthesia bomb is suitable for the scenes of animal control, emergency security and protection and the like, and the technical innovation and the practical value are achieved at the same time.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of anesthesia tools, and relates to an anesthesia bomb combining a microneedle and a microfluidic chip. BACKGROUND

[0002] In recent years, with the maturity of MEMS technology, microneedle technology and microfluidic technology have been extensively researched and rapidly developed. Among them, the microneedle has the characteristics of small volume and can deliver drugs, and relying on MEMS technology can realize painless, minimally invasive and efficient transdermal drug delivery. The microfluidic chip can significantly improve the drug delivery rate, is convenient to operate, and is integrated with sample processing, transportation, separation, detection and other functions to realize rapid detection of small samples. Both have similarities in preparation materials and processing technology, and are applied to fields such as biochemical analysis, medical diagnosis and drug delivery, and have natural advantages of combination. However, the existing combination schemes are mostly focused on clinical diagnosis and conventional drug delivery scenes, and have not been designed for the special needs of anesthesia bomb heads in war environments, resulting in the inability to adapt to the core requirements of rapid release and accurate control of anesthetic drugs in war scenes. In addition, the adaptation of microneedle array and microfluidic chip flow channel, microneedle minimally invasive drug delivery and microfluidic rate regulation has not formed a mature solution suitable for anesthesia bomb head applications, and it is difficult to meet the needs of rapid anesthesia of targets and accurate drug release in war scenes. SUMMARY

[0003] The purpose of the present application is to solve the problem that the existing combination scheme of microneedle and microfluidic chip focuses on clinical and conventional drug delivery scenes, does not adapt to the needs of anesthesia bomb heads, and the flow channel connection and rate regulation cannot be adapted. The present application provides an anesthesia bomb combining a microneedle and a microfluidic chip.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: An anesthesia bomb combining a microneedle and a microfluidic chip, comprising: a tail wing assembly, a piston, an anesthetic drug capsule, a microfluidic chip, a wind cap, a needle and a shell. The wind cap is arranged at one end of the shell, and the tail wing assembly is arranged at the other end of the shell. The tail wing assembly is used to keep the shell stable in flight. The piston and the piezoelectric control system are both arranged inside the shell. One end of the piston is provided with a propellant, and the propellant is linked with the discharge end of the energy storage capacitor of the piezoelectric control system. The discharge trigger point of the energy storage capacitor ignites the propellant. The anesthetic drug capsule is arranged at the other end of the piston. When the piston is driven forward by the propellant, it breaks the anesthetic drug capsule. The microfluidic chip is arranged inside the wind cap. The liquid inlet end of the microfluidic chip is in communication with the liquid outlet end of the anesthetic drug capsule, and is used to regulate the delivery of anesthetic drugs. One end of the needle extends outward through the wind cap and is used to pierce the target. One end of the needle is connected with the liquid outlet end of the microfluidic chip.

[0005] A further improvement of the present invention is that: Furthermore, the tail fin assembly includes a folding elastic tail fin, a hinge shaft, and a constraint collar; the folding elastic tail fin is connected to the housing via the hinge shaft; the constraint collar folds the folding elastic tail fin at the tail of the housing; there are several folding elastic tail fins, which are evenly distributed along the outer periphery of the tail of the housing.

[0006] Furthermore, the tail fin assembly is used to maintain the stability of the shell during flight. Specifically, after the tranquilizer dart leaves the barrel, the restraint ring automatically detaches under the action of air resistance and centrifugal force of the projectile. The folding elastic tail fin unfolds outward by its own elastic restoring force and hinge structure to form a stable cross-shaped airfoil, providing sufficient aerodynamic stability during flight.

[0007] Furthermore, the piezoelectric control system includes a piezoelectric system and a mechanical switch; the piezoelectric system is disposed inside the housing; the mechanical switch is disposed inside the wind cap, and the piezoelectric system controls the closing of the mechanical switch; the microfluidic chip is disposed at one end of the mechanical switch; the mechanical switch controls the drug flow between the microfluidic chip and the anesthetic capsule; the mechanical switch remains open before the anesthetic projectile hits the target; after the anesthetic projectile hits the target, the piezoelectric system controls the mechanical switch to close.

[0008] Furthermore, the piezoelectric system includes a pressure sensor, a piezoelectric ceramic, an energy harvesting chip, an energy storage capacitor, and a diode, wherein the pressure sensor, piezoelectric ceramic, energy harvesting chip, energy storage capacitor, diode, and mechanical switch are electrically connected in sequence. Furthermore, the piezoelectric system controls the closing of the mechanical switch, specifically as follows: After the needle hits the target, the pressure sensor transmits the sensed mechanical impact signal to the piezoelectric ceramic, which generates free charge. The free charge is rectified and regulated by the energy harvesting chip, converted into stable DC, and stored in the energy storage capacitor to ensure the power required for instantaneous release. The diode plays a unidirectional conducting role in the circuit, preventing the charge in the energy storage capacitor from leaking back towards the piezoelectric ceramic and the energy harvesting chip. The mechanical switch remains open until the needle hits the target, and after the needle hits the target, the mechanical switch is triggered by inertia to close, allowing the energy storage capacitor to quickly release electrical energy to power the microfluidic chip.

[0009] Furthermore, the fixing structure includes a fixing bracket and a drug capsule limiting ring. The fixing bracket, through its fixed connection with the inner wall of the housing, provides stable mounting support for the piezoelectric control system and the microfluidic chip, preventing displacement or damage during projectile launch and flight. Simultaneously, the drug capsule limiting ring is arranged inside the housing to limit and fix the anesthetic drug capsule, ensuring that the anesthetic drug capsule is in the accurate position and maintains structural stability during piston push, preventing displacement or loosening that would affect drug release.

[0010] Furthermore, the fixing structure also includes a piston guide sleeve; the piston guide sleeve is fixed inside the housing and sleeved on the outer circumference of the piston. The inner diameter of the piston guide sleeve and the outer diameter of the piston have a gap to ensure that the piston makes a smooth linear movement in the axial direction of the housing, while avoiding excessive friction due to overly tight fit or movement deviation due to overly loose fit.

[0011] Furthermore, the needle includes a microneedle array and a silicon substrate containing a pressure sensor. The microneedle array is fixed to the side of the silicon substrate facing the target. The microfluidic chip integrates a microchannel for liquid delivery. The inlet end of the microfluidic chip is connected to an anesthetic capsule to receive the liquid. The outlet end of the microfluidic chip is connected to the silicon substrate where the needle is located, so that the liquid after being regulated by the microfluidic chip can smoothly enter the microneedle array and be injected into the target body.

[0012] Furthermore, a pressure sensor integrated on the silicon substrate is connected to a microfluidic chip; a switch is provided between the liquid outlet of the microfluidic chip and the silicon substrate; the pressure sensor integrated on the silicon substrate senses the local pressure signal when the microneedle array pierces the target tissue and sends the signal to the microfluidic chip; the microfluidic chip determines whether the magnitude of the local pressure signal exceeds a preset pressure threshold; if it does, the switch between the microfluidic chip and the silicon substrate is activated, allowing the drug solution to enter the silicon substrate.

[0013] Furthermore, the fabrication process of the microneedle array includes: a) A metal electrode film with a thickness of 50-100 nm was prepared on the surface of a silicon substrate using magnetron sputtering. b) Coat the surface of the metal electrode film with SU-8 epoxy resin containing photoinitiator with a thickness of 300-350μm, and pattern the SU-8 epoxy resin into cylinders with a diameter of 100μm by ultraviolet photolithography to define the initial shape of the microneedles. c) The patterned SU-8 epoxy resin is pre-baked at a preset temperature and then post-baked at 110-120℃ for 60-90 min to obtain a cross-linked cylindrical structure. d) A spin-coating process is used to fill the gaps between the cross-linked cylindrical structures with sacrificial polymer; e) Coating the entire structure surface with a copper layer of 600 nm thickness using an electron beam deposition process; f) Etch the copper layer at 25-30°C using a sulfuric acid solution with a mass fraction of 10-15%, retaining a rectangular copper pattern, which asymmetrically covers the top of the cross-linked cylindrical structure and the sacrificial polymer surface on one side of each cross-linked cylindrical structure. g) The etched structure is etched using reactive ion etching process, and the etching gas is a mixture of CF4 and O2. h) The microneedle array is obtained by soaking the microneedle in acetone solution at 50-60°C to remove the sacrificial polymer.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention features a tail fin assembly that automatically deploys after launch to form a stable airfoil, ensuring flight accuracy. It utilizes a piezoelectric control system powered by impact signals, coupled with a mechanical switch for precise triggering upon impact. Simultaneously, a fixed structure, employing a bracket, limiting ring, and guide sleeve, ensures stable, displacement-free operation of all components during launch and flight. A microfluidic chip regulates drug delivery, combined with a pressure-sensing microneedle array, releasing the drug only when it reaches a pressure threshold upon tissue penetration, preventing drug waste and misrelease. This invention achieves stable flight, precise triggering, and controllable drug delivery for the anesthetic projectile, improving anesthesia efficiency and safety. It is suitable for animal control, emergency security, and other scenarios, combining technological innovation with practical value. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram illustrating the working principle of the anesthetic projectile of the present invention; Figure 2 This is a schematic diagram of the anesthetic bullet combining microneedles and microfluidic chips of the present invention. Figure 3 Simplified circuit diagram for injecting anesthetic darts; Figure 4 This is a schematic diagram of the microneedle array structure; Figure 5 This is a schematic diagram of the fabrication process of microneedle arrays on a silicon substrate.

[0017] Among them, 1-folding elastic tail fin, 2-piezoelectric system, 3-piston, 4-anesthetic capsule, 5-mechanical switch, 6-microfluidic chip, 7-wind cap, 8-needle, 9-shell, 10-fixed bracket, 11-capsule limiting ring, 12-piston guide sleeve, 13-microneedle array, 14-silicon substrate. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0024] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 After the tranquilizer gun is fired, the propellant gas pushes the injection projectile through the piston. The injection projectile gains significant kinetic energy through the piston and flies out of the muzzle. Upon hitting the target, the pressure sensor activates the injection circuit. The microneedle array of the projectile penetrates the target, triggering the projectile fuse, igniting the propellant in the piston groove inside the projectile, and pushing the piston to compress the anesthetic capsule. The capsule delivers the drug through a microfluidic chip, and the anesthetic drug is injected through the microneedle array, allowing the anesthetic drug to enter the target's body.

[0025] See Figure 2 The present invention discloses an anesthetic projectile head combining microneedles and microfluidic chips, comprising: a tail fin assembly, a piston 3, an anesthetic sac 4, a microfluidic chip 6, a wind cap 7, a needle 8, and a shell 9; The wind cap 7 is located at one end of the housing 9, and the tail fin assembly is located at the other end of the housing 9. The tail fin assembly is used to maintain the stability of the housing 9 during flight. The piston 3 and the piezoelectric control system are both located inside the housing 9. One end of the piston 3 is provided with a propellant. The propellant is linked to the discharge terminal of the energy storage capacitor of the piezoelectric control system. The discharge of the energy storage capacitor triggers the ignition of the propellant. The anesthetic sac 4 is located at the other end of the piston 3. When the piston 3 is driven forward by the propellant, it crushes the anesthetic sac 4. The microfluidic chip 6 is located inside the wind cap 7. The inlet end of the microfluidic chip 6 is connected to the outlet end of the anesthetic sac 4 and is used to regulate the delivery of anesthetic drugs. One end of the needle 8 passes through the wind cap 7 and extends outward to pierce the target. One end of the needle 8 is connected to the outlet end of the microfluidic chip 6.

[0026] The tail fin assembly includes a folding elastic tail fin 1, a hinge shaft, and a constraint collar; the folding elastic tail fin 1 is connected to the housing 9 via the hinge shaft; the constraint collar folds the folding elastic tail fin 1 at the tail of the housing 9; there are several folding elastic tail fins 1, which are evenly distributed along the outer periphery of the tail of the housing 9.

[0027] The tail fin assembly is used to maintain the stability of the shell 9 during flight. Specifically, after the anesthetic projectile leaves the barrel, the restraint ring automatically detaches under the action of air resistance and centrifugal force of the projectile. The folding elastic tail fin 1 unfolds outward by its own elastic restoring force and hinge structure to form a stable cross-shaped airfoil, providing sufficient aerodynamic stability during flight and ensuring that the anesthetic projectile maintains its predetermined trajectory in space.

[0028] The piezoelectric control system includes a piezoelectric system 2 and a mechanical switch 5; the piezoelectric system 2 is disposed inside the housing 9; the mechanical switch 5 is disposed inside the wind cap 7, and the piezoelectric system 2 controls the closing of the mechanical switch 5; the microfluidic chip 6 is disposed at one end of the mechanical switch 5; the mechanical switch 5 controls the drug flow between the microfluidic chip 6 and the anesthetic sac 4; the mechanical switch 5 remains open before the anesthetic projectile hits the target; after the anesthetic projectile hits the target, the piezoelectric system 2 controls the mechanical switch 5 to close.

[0029] See Figure 3 The piezoelectric system 2 includes a pressure sensor, a piezoelectric ceramic, an energy harvesting chip, an energy storage capacitor, and a diode. The pressure sensor, piezoelectric ceramic, energy harvesting chip, energy storage capacitor, diode, and mechanical switch 5 are electrically connected in sequence. The piezoelectric system 2 controls the closing of the mechanical switch 5 as follows: After the needle 8 hits the target, the pressure sensor transmits the sensed mechanical impact signal to the piezoelectric ceramic, which generates free charge. The free charge is rectified and regulated by the energy harvesting chip, converted into stable DC, and stored in the energy storage capacitor to ensure the power required for instantaneous release. The diode plays a unidirectional conducting role in the circuit, preventing the charge in the energy storage capacitor from being discharged in the reverse direction towards the piezoelectric ceramic and the energy harvesting chip. The mechanical switch 5 remains open before the hit, and closes due to inertia after the needle 8 hits the target, enabling the energy storage capacitor to quickly release electrical energy to power the microfluidic chip 6.

[0030] The fixing structure includes a fixing bracket 10 and a drug capsule limiting ring 11. The fixing bracket 10 is fixedly connected to the inner wall of the housing 9 to provide stable installation support for the piezoelectric control system and the microfluidic chip 6, preventing them from being displaced or damaged during projectile launch and flight. At the same time, the drug capsule limiting ring 11 is arranged inside the housing 9 to limit and fix the anesthetic drug capsule 4, ensuring that the anesthetic drug capsule 4 is in the accurate position and maintains structural stability during the piston 3 push, preventing displacement or loosening that would affect the release of the drug.

[0031] The fixing structure also includes a piston guide sleeve 12; the piston guide sleeve 12 is fixed inside the housing 9 and sleeved on the outer periphery of the piston 3. The inner diameter of the piston guide sleeve 12 and the outer diameter of the piston 3 have a gap, which is used to ensure that the piston 3 makes a smooth linear movement in the axial direction of the housing 9, while avoiding excessive friction due to overly tight fit or movement deviation due to overly loose fit.

[0032] See Figure 4 The needle 8 includes a microneedle array 13 and a silicon substrate 14 containing a pressure sensor. The microneedle array 13 is fixed to the side of the silicon substrate 14 facing the target. The microfluidic chip 6 integrates a microchannel for liquid delivery. The inlet end of the microfluidic chip 6 is connected to the anesthetic capsule 4 to receive the liquid. The outlet end of the microfluidic chip 6 is connected to the silicon substrate 14 where the needle 8 is located, so that the liquid after being regulated by the microfluidic chip 6 can smoothly enter the microneedle array 13 and be injected into the target body.

[0033] The pressure sensor integrated on the silicon substrate 14 is connected to the microfluidic chip 6; a switch is provided between the liquid outlet end of the microfluidic chip 6 and the silicon substrate 14; the pressure sensor integrated on the silicon substrate 14 senses the local pressure signal when the microneedle array 13 pierces the target tissue and sends the signal to the microfluidic chip 6; the microfluidic chip 6 determines whether the magnitude of the local pressure signal exceeds a preset pressure threshold; if it does, the switch between the microfluidic chip 6 and the silicon substrate 14 is turned on, allowing the drug solution to enter the silicon substrate 14.

[0034] See Figure 5 The fabrication process of the microneedle array 13 includes: a) A metal electrode film with a thickness of 50-100 nm was prepared on the surface of a silicon substrate 14 using a magnetron sputtering process; b) Coat the surface of the metal electrode film with SU-8 epoxy resin containing photoinitiator with a thickness of 300-350μm, and pattern the SU-8 epoxy resin into cylinders with a diameter of 100μm by ultraviolet photolithography to define the initial shape of the microneedles. c) The patterned SU-8 epoxy resin is pre-baked at a preset temperature and then post-baked at 110-120℃ for 60-90 min to obtain a cross-linked cylindrical structure. d) A spin-coating process is used to fill the gaps between the cross-linked cylindrical structures with sacrificial polymer; e) Coating the entire structure surface with a copper layer of 600 nm thickness using an electron beam deposition process; f) Etch the copper layer at 25-30°C using a sulfuric acid solution with a mass fraction of 10-15%, retaining a rectangular copper pattern, which asymmetrically covers the top of the cross-linked cylindrical structure and the sacrificial polymer surface on one side of each cross-linked cylindrical structure. g) The etched structure is etched using reactive ion etching process, and the etching gas is a mixture of CF4 and O2. h) The microneedle array 13 was obtained by soaking the microneedle in acetone solution at 50-60°C to remove the sacrificial polymer.

[0035] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An anesthetic bullet combining microneedles and a microfluidic chip, characterized in that, include: Tail fin assembly, piston (3), anesthetic capsule (4), microfluidic chip (6), wind cap (7), needle (8) and housing (9); The wind cap (7) is located at one end of the housing (9), and the tail fin assembly is located at the other end of the housing (9). The tail fin assembly is used to maintain the stability of the housing (9) during flight. The piston (3) and the piezoelectric control system are both located inside the housing (9). One end of the piston (3) is provided with a propellant. The propellant is linked with the discharge end of the energy storage capacitor of the piezoelectric control system. The discharge of the energy storage capacitor triggers the ignition of the propellant. The anesthetic sac (4) is located at the other end of the piston (3). When the piston (3) is driven forward by the propellant, it crushes the anesthetic sac (4). The microfluidic chip (6) is located inside the wind cap (7). The inlet end of the microfluidic chip (6) is connected to the outlet end of the anesthetic sac (4) to regulate the delivery of anesthetic drugs. One end of the needle (8) passes through the wind cap (7) and extends outward to pierce the target. One end of the needle (8) is connected to the outlet end of the microfluidic chip (6).

2. The anesthetic bullet combining microneedles and a microfluidic chip according to claim 1, characterized in that, The tail fin assembly includes a folding elastic tail fin (1), a hinge shaft, and a constraint collar; the folding elastic tail fin (1) is connected to the housing (9) via the hinge shaft; the constraint collar folds the folding elastic tail fin (1) at the tail of the housing (9); the number of folding elastic tail fins (1) is several, and they are evenly distributed along the outer periphery of the tail of the housing (9).

3. The anesthetic bullet combining microneedles and microfluidic chips according to claim 2, characterized in that, The tail fin assembly is used to maintain the stability of the shell (9) during flight. Specifically, after the anesthetic bullet leaves the barrel, the restraint ring automatically falls off under the action of air resistance and centrifugal force of the bullet. The folding elastic tail fin (1) unfolds outward by its own elastic restoring force and hinge structure to form a stable cross airfoil, providing sufficient aerodynamic stability during flight.

4. The anesthetic bullet combining microneedles and microfluidic chips according to claim 3, characterized in that, The piezoelectric control system includes a piezoelectric system (2) and a mechanical switch (5); the piezoelectric system (2) is located inside the housing (9); the mechanical switch (5) is located inside the wind cap (7), and the piezoelectric system (2) controls the closing of the mechanical switch (5); the microfluidic chip (6) is located at one end of the mechanical switch (5); the mechanical switch (5) controls the flow of drug between the microfluidic chip (6) and the anesthetic sac (4); the mechanical switch (5) remains open before the anesthetic projectile hits the target; after the anesthetic projectile hits the target, the piezoelectric system (2) controls the mechanical switch (5) to close.

5. The anesthetic bullet combining microneedles and a microfluidic chip according to claim 4, characterized in that, The piezoelectric system (2) includes a pressure sensor, a piezoelectric ceramic, an energy harvesting chip, an energy storage capacitor, and a diode. The pressure sensor, piezoelectric ceramic, energy harvesting chip, energy storage capacitor, diode, and mechanical switch (5) are electrically connected in sequence. The piezoelectric system (2) controls the closing of the mechanical switch (5) as follows: After the needle (8) hits the target, the pressure sensor transmits the sensed mechanical impact signal to the piezoelectric ceramic, which generates free charge. The free charge is rectified and regulated by the energy harvesting chip, and then converted into a stable DC and stored in the energy storage capacitor to ensure that it has the power required for instantaneous release. The diode plays a unidirectional conduction role in the circuit to prevent the charge in the energy storage capacitor from being discharged in the opposite direction to the piezoelectric ceramic and the energy harvesting chip. The mechanical switch (5) remains open before the hit. After the needle (8) hits the target, the mechanical switch (5) is closed by inertial trigger, so that the energy storage capacitor can quickly release electrical energy to power the microfluidic chip (6).

6. The anesthetic bullet combining microneedles and a microfluidic chip according to claim 5, characterized in that, The fixed structure includes a fixed bracket (10) and a drug capsule limiting ring (11). The fixed bracket (10) is fixedly connected to the inner wall of the housing (9) to provide stable installation support for the piezoelectric control system and the microfluidic chip (6) and prevent them from being displaced or damaged during the launch and flight of the projectile. At the same time, the drug capsule limiting ring (11) is arranged inside the housing (9) to limit and fix the anesthetic drug capsule (4) to ensure that the anesthetic drug capsule (4) is in the accurate position and maintains structural stability during the piston (3) push, and to prevent displacement or loosening that would affect the release of the drug.

7. The anesthetic bullet combining microneedles and a microfluidic chip according to claim 6, characterized in that, The fixing structure also includes a piston guide sleeve (12); the piston guide sleeve (12) is fixed inside the housing (9) and sleeved on the outer periphery of the piston (3). The inner diameter of the piston guide sleeve (12) and the outer diameter of the piston (3) have a gap to ensure that the piston (3) makes a smooth linear movement in the axial direction of the housing (9), while avoiding excessive friction due to tight fit or movement deviation due to loose fit.

8. The anesthetic bullet combining microneedles and microfluidic chips according to claim 7, characterized in that, The needle (8) includes a microneedle array (13) and a silicon substrate (14) containing a pressure sensor. The microneedle array (13) is fixed to the side of the silicon substrate (14) facing the target. The microfluidic chip (6) integrates a microchannel for liquid delivery. The inlet end of the microfluidic chip (6) is connected to the anesthetic capsule (4) to receive the liquid. The outlet end of the microfluidic chip (6) is connected to the silicon substrate (14) where the needle (8) is located, so that the liquid after being regulated by the microfluidic chip (6) can smoothly enter the microneedle array (13) and be injected into the target body.

9. The anesthetic bullet combining microneedles and a microfluidic chip according to claim 8, characterized in that, The pressure sensor integrated on the silicon substrate (14) is connected to the microfluidic chip (6); a switch is provided between the liquid outlet end of the microfluidic chip (6) and the silicon substrate (14); the pressure sensor integrated on the silicon substrate (14) senses the local pressure signal when the microneedle array (13) pierces the target tissue and sends the signal to the microfluidic chip (6); the microfluidic chip (6) determines whether the magnitude of the local pressure signal exceeds the preset pressure threshold; if it exceeds the threshold, the switch between the microfluidic chip (6) and the silicon substrate (14) is turned on, so that the drug solution enters the silicon substrate (14).

10. The anesthesia projectile combining microneedles and microfluidic chips according to claim 9, characterized in that, The fabrication process of the microneedle array (13) includes: a) A metal electrode film with a thickness of 50-100 nm was prepared on the surface of a silicon substrate (14) using a magnetron sputtering process; b) Coat the surface of the metal electrode film with SU-8 epoxy resin containing photoinitiator with a thickness of 300-350μm, and pattern the SU-8 epoxy resin into cylinders with a diameter of 100μm by ultraviolet photolithography to define the initial shape of the microneedles. c) The patterned SU-8 epoxy resin is pre-baked at a preset temperature and then post-baked at 110-120℃ for 60-90 min to obtain a cross-linked cylindrical structure. d) A spin-coating process is used to fill the gaps between the cross-linked cylindrical structures with sacrificial polymer; e) Coating the entire structure surface with a copper layer of 600 nm thickness using an electron beam deposition process; f) Etch the copper layer at 25-30°C using a sulfuric acid solution with a mass fraction of 10-15%, retaining a rectangular copper pattern, which asymmetrically covers the top of the cross-linked cylindrical structure and the sacrificial polymer surface on one side of each cross-linked cylindrical structure. g) The etched structure is etched using reactive ion etching process, and the etching gas is a mixture of CF4 and O2. h) The microneedle array was obtained by soaking the microneedle in acetone solution at 50-60°C to remove the sacrificial polymer.

Images