Ultrasonic Atomization Research Articles

Justification and implementation of the layer thickness control method in ultrasonic spraying

Relevance. The need for the development and widespread use of the ultrasonic spraying method, which has unique advantages, to solve the most pressing problems of modern industry. In particular: minimal, of all known methods, energy consumption for the implementation of the process, the possibility of forming fine droplets without the use of gas under pressure, regulating the dispersion of the formed aerosol by the parameters of the emitter, etc. However, for widespread practical use of the ultrasonic spraying method, it is necessary to ensure spraying conditions with a specified dispersion and productivity. In this regard, there is a need to develop a method for controlling and maintaining the necessary and sufficient thickness of the liquid layer on the surface of the piezoelectric transducer of the atomizer, the spraying of which will ensure, at a given spraying performance, the formation of an aerosol with the smallest deviation in the size of the formed droplets relative to the average value. It is proposed to control the thickness of the liquid layer by identifying the dependence of the resonant frequency of the piezoelectric transducer of the atomizer on the thickness of the liquid film on the oscillating surface of the atomizer. Aim. To develop a method and means for controlling the thickness of the layer of sprayed liquid by changing the resonant frequency of the ultrasonic oscillatory system and maintaining the optimal value of the layer thickness by changing the amplitude of vibrations of the surface of the ultrasonic sprayer. Objects. Liquid atomizing with ultrasonic high-amplitude vibrations. Methods. Obtaining the frequency characteristics of ultrasonic oscillatory systems, analyzing changes in the amplitude-frequency characteristics of oscillating systems and identifying criteria that allow monitoring and managing the ultrasonic spraying. Results. The authors have proposed and developed the method for indirectly monitoring the thickness of a sprayed liquid layer on the oscillating surface of an ultrasonic atomizer, based on measuring the resonant frequency of an ultrasonic oscillating system. The possibility of implementing the method and its practical application is caused by the fact that in the working range of layer thicknesses of the sprayed liquid, the change in the resonant frequency can reach 100 Hz, and with a frequency measurement accuracy of 1 Hz, the accuracy of determining the layer thickness will be no more than 2% of the working layer thickness. The identified dependencies and certain values of possible ranges of changes in the controlled parameter made it possible for the first time to develop a method for automatically controlling ultrasonic spraying, ensuring the maintenance of optimal modes of ultrasonic influence (amplitude of vibrations of the spray surface) and the thickness of the layer of sprayed liquid.

An Investigation of the Metal Powder Ultrasound Atomisation Process of 316L Stainless Steel.

This paper presents the results of a study on the atomisation process of 316L material. The primary objective of the study was to obtain the highest quality, quantity and yield of 316L metal powder for the established atomisation parameters (torch current and wire feed speed) at the assumed process time. Using experiment planning according to the Taguchi method, 16 pairs of controllable variable parameters were developed. It was observed that the low current high-wire speed configuration resulted in the formation of a considerable amount of molten metal on the sonotrode platform. This phenomenon prevented the ultrasound system from working properly, so some of the processes were interrupted. The results obtained from the tests showed that torch current and wire feed speed are parameters that have a significant impact on the efficiency of the ultrasonic atomisation process. The highest efficiency was achieved by the process with a torch current of 100 A and a wire feed speed of 9 mm/s.

Ultrasonic-assisted radial jet reattachment atomizer

Ultrasonic atomization, a powerful method using high-frequency sound waves, has gained notable significance across diverse industries due to its capacity to disintegrate liquids into very fine droplets. The use of ultrasonic vibrations for spray formation can effectively address the challenges associated with conventional methods, including the requirement for high temperatures and high-pressure fluids. Compared to conventional methods, ultrasonic atomizers can deliver a spray with lower velocity, operate at lower temperatures, produce smaller particle sizes, achieve high evaporation rates, and impose low mechanical stress. The radial jet reattachment (RJR) nozzle is a unique design to modify a jet’s flow and improve its transport characteristics, especially in air drying and cooling processes. In this paper, a novel technology is utilized with the combination of an RJR nozzle and ultrasonic atomization to atomize most liquids. The corresponding atomization rate, mist droplet size distribution, and mist droplet velocity distribution, influenced by liquid properties, temperature change, transducer mesh pore size, and applied voltage have been investigated in this paper. The energy consumption ratios, defined as the ratio of thermal energy required to evaporate liquid divided by ultrasonic energy, are analyzed based on atomization rate and applied power, showing very promising results among atomizing methods. Furthermore, the results in terms of the droplet average diameter and mean velocity as well as the resultant volumetric flow rate under different operating conditions and for all working fluids considered have been correlated with the aid of non-dimensional parameters. In addition, certain potential applications based on the remarkable characteristics of the ultrasonic-assisted RJR atomizer such as misting liquids and spray drying are highlighted.

Reducing the diameter of the atomized particles by coating polymer membrane on the inner wall of micro-tapered holes of the ultrasonic mesh atomizers

Atomized inhalation therapy with its rapid efficacy, low side effects and high medicine utilization, has become a crucial method for treating respiratory diseases. The depth of atomized particles deposition in the respiratory tract mainly depends on the particle diameter, making the reducing of the atomized particle size crucial for medicine deposit in lung. In the existing literatures, for the widely used dynamic mesh atomizer, the majority of the researches focused on the mechanical structure and the vibration characteristics of the atomizers. However, there is little researches on the micro-tapered holes of the metal sheet of the atomizer, despite the fact that the diameter of these tapered holes determines the size of the atomized particles. Due to the processing technology, the diameter of the micro-tapered holes cannot be further reduced, which greatly limits the development of the dynamic mesh atomizer in inhalation therapy. In this study, we consider the use of polymer coating on the inner wall of the micro-tapered holes to eliminate burrs, reduce the diameter of the holes, and ultimately reduce the size of the atomized particles. A theoretical model of the initial thickness of the coating polymer membrane and the rupture depth under the uniform air pressure applied to a single tapered hole was established. The metal sheets with different initial coating thicknesses were processed to verify the theoretical model by observing the quality of the inner surface and measuring the diameter of the holes. The particle size measurement experiment results show that when the initial coating thickness was 3 μm and 4.5 μm, the average particle sizes were reduced by 12.5 % and 23.2 %, respectively. Therefore, the proposed method can effectively reduce the atomized particles size, which helps to efficiently deposit atomized drugs in the lungs.

Augmentation of hemispherical solar distiller performance utilizing ultrasound atomizers and carbon black nanoparticles

Addressing the water shortage and environmental concerns, this study suggests several modifications to the hemispheric solar still aiming to increase productivity while maintaining a competitive water price. The distiller is enhanced with an ultrasonic atomizer to improve water evaporation throughout the day. The study investigates the impacts of both the water height above the atomizers and their quantity. The system performance was investigated under three cases of modified design, Case 1; integration with atomizers, Case 2; combined atomizers with on–off timer, Case 3; augmented carbon black nanoparticles with atomizers and timer. Results indicated that with four atomizers and 1 cm water height above them, the productivity reached 3.966 L/m2, with exergetic and energetic efficiencies of 1.87 % and 23.22 %, respectively. Additionally, an on–off timer is incorporated into the unit to test performance under different on–off durations (15 min, 20 min, and 25 min). With a 20-minute interval, these values escalated to production rate, energy, and exergy efficiency. 6.393 L/m2, 38.75 %, and 2.95 %, respectively. Furthermore, carbon black nanoparticle implementation is integrated into the distiller alongside intermittent atomizer operation. This integration further boosts productivity to 7.321 L/m2, significantly improving exergy (3.81 %) and energy efficiencies (44.22 %). Compared to a non-modified hemispheric distiller, the modified distillers show productivity enhancement ratios of 40.5 %, 104.1 %, and 137.1 % for the three cases, respectively. From an economic perspective, the water price is substantially lower for the modified distillers, ranging from 0.0128 to 0.0205 USD/L, compared to 0.0229 USD/L for the traditional distiller.

Study on the influence of aerosol atomization by ultrasonic atomization on coal spontaneous combustion

ABSTRACT Influenced by the complex environment and the nature of process materials in goaf, the prevention and control of spontaneous combustion of coal (CSC) in the deep part of goaf were facing many difficulties. To investigate the performance of ultrasonic atomized aerosols, a series of atomization experiments were conducted using a self-developed ultrasonic atomization device. The main conclusions are as follows: under the same atomization conditions, the atomized particle sizes of several inhibitors (except PAS-W) are concentrated in the <8 μm range, with a content of more than 88%, indicating that the aerosol particles produced by ultrasonic atomization are small in size and uniform in distribution. Compared with water and MgCl2 inhibitors, aerosol particles produced by PAS-W are less likely to pass through the voids of the coal body, and have poorer permeability and diffusivity. As the temperature increases, the viscosity and surface tension of the inhibitor decrease, and the percentage of aerosol particles with particle size <8 μm produced by ultrasonic atomization is more than 88%, indicating that the atomization effect is improved. After increasing the temperature, the contact angle between PAS-W inhibitor and coal reduces from 54.7° to 40.8°, and the wettability is better. Compared with raw coal, the final temperature of the PAS-W aerosol treated coal sample is delayed 21.86°C, and has significant retarding property. When the wind speed is 3 m/s, the effect of PAS-W aerosol particle generation, permeability, and particle size distribution is the best. The results of the study are of great significance in improving the ultrasonic atomized aerosol fire prevention technology and realizing large-scale CSC prevention in goaf.

Application of Quantitative Magnetic Resonance Imaging (QMRI) to Evaluate the Effectiveness of Ultrasonic Atomization of Water in Truffle Preservation.

Truffles of the Tuber genus (Pezizales, Ascomycetes) are among the most valuable and expensive foods, but their shelf life is limited to 7-10 days when stored at 4 °C. Alternative preservation methods have been proposed to extend their shelf life, though they may alter certain quality parameters. Recently, a hypogeal display case equipped with an ultrasonic humidity system (HDC) was developed, extending the shelf life to 2-3 weeks, depending on the truffle species. This study assesses the efficacy of HDC in preserving Tuber melanosporum and Tuber borchii ascomata over 16 days, using quantitative magnetic resonance imaging (QMRI) to monitor water content and other parameters. Sixteen T. melanosporum and six T. borchii ascomata were stored at 4 °C in an HDC or a static fridge (SF) as controls. QMRI confirmed that T. borchii has a shorter shelf life than T. melanosporum under all conditions. HDC reduced the rate of shrinkage, water, and mass loss in both species. Additionally, the Apparent Diffusion Coefficient (ADC), longitudinal relaxation time (T1), and transverse relaxation time (T2), which reflect molecular changes, decreased more slowly in HDC than SF. QMRI proves useful for studying water-rich samples and assessing truffle preservation technologies. Further optimization of this method for industrial use is needed.

Impact of piezoelectric driving waveform on performance characteristics of vibrating mesh atomizer (VMA)

Vibrating mesh atomizer (VMA) is a specific type of ultrasonic atomizer known for its low power consumption and production of uniformly fine droplets. While previous research has provided a basic understanding of VMA operation, it has primarily focused on driving the piezoelectric actuator with continuous and symmetrical waveforms, such as sine and square waveforms. This study aims to experimentally investigate the impact of different driving waveforms on the ultrasonic atomization process and the associated performance characteristics. Specifically, the effects of pulse waveforms (Gauss and Lorentz pulse) were analyzed with high rates of energy deposition and asymmetrical hybrid waveforms (trapezia and absolute sine), featuring distinct negative cycles, by comparing them with conventional symmetrical waveforms (sine and square). Pulse waveforms suppress the growing stage but provide a high flux of input energy, facilitating the detachment of liquid into fine droplets, resulting in uniformly distributed droplets with VMDs of 5.84 μm and 4.71 μm for Gauss and Lorentz waveforms, respectively. Conversely, shorter negative cycles in asymmetrical hybrid waveforms reduce liquid suction into the micronozzle, leading to higher energy flux during subsequent positive cycles that promote the growing stage, producing larger droplets with VMDs of 10.82 μm and 11.86 μm for trapezia and absolute (abs) sine waveforms, respectively. Additionally, high-speed imaging reveals irregular pulsating behaviors in the atomization process when using pulse waveforms, suggesting a reciprocating-pump-like operation mechanism in VMA atomization. These new insights contribute to an improved understanding of the atomization mechanism in VMAs.

Effect of Spray Characteristic Parameters on Friction Coefficient of Ultra-High-Strength Steel against Cemented Carbide.

Ultra-high-strength steels have been considered an essential material for aviation components owing to their excellent mechanical properties and superior fatigue resistance. When machining these steels, severe tool wear frequently results in poor surface quality and low machining efficiency, which is intimately linked to the friction behavior at the tool-workpiece interface. To enhance the service life of tools, the adoption of efficient cooling methods is paramount. However, the understanding of friction behavior at the tool-workpiece interface under varying cooling conditions remains limited. In this work, both air atomization of cutting fluid (AACF) and ultrasonic atomization of cutting fluid (UACF) were employed, and their spray characteristic parameters, including droplet size distribution, droplet number density, and droplet velocity, were evaluated under different air pressures. Discontinuous sliding tests were conducted on the ultra-high-strength steel against cemented carbide and the effect of spray characteristic parameters on the adhesion friction coefficient was studied. The results reveal that ultrasonic atomization significantly improved the uniformity of droplet size distribution. An increase in air pressure resulted in an increase in both droplet number density and droplet velocity under both AACF and UACF conditions. Furthermore, the thickness of the liquid film was strongly dependent on the spray characteristic parameters. Additionally, UACF exhibited a reduction of 4.7% to 9.8% in adhesion friction coefficient compared to AACF. UACF provided the appropriate combination of spray characteristic parameters, causing an increased thickness of the liquid film, which subsequently exerted a positive impact on reducing the adhesion friction coefficient.

Layer formation, morphology and photoluminescent properties of ultrasonic spray of pre-formed YVO4:Eu and SiO2 coated ZnS:Mn nanoparticles

In this work, we study the coating process and coating quality of photoluminescent particles deposited on a glass surface in terms of particle distribution and associated film continuity. The dispersion process of commercial ZnS:Mn particles and YVO4:Eu particles synthesized by microwave reactor in aqueous solutions onto solid surface was performed using an ultrasonic atomizer. Two methods of particle deposition were used, one by moving the substrates while spraying and in the second the substrates were not moved. The measured zeta potential values of 42.9 mV and 45.3 mV, respectively, show that the dispersion of YVO4:Eu nanoparticles, in water, is stable at concentrations of 1.2 wt% and 2.4 wt% without the addition of capping agents. It was also found that the dispersion area increases as the flow rate increases from 1 ml/min to 3 ml/min at constant suspension concentration and spraying time. To stabilize the ZnS:Mn particles in solution, either surfactants or a silica capping layer prepared by a sol-gel process were used.The dispersion area encompassing the major amount of dispersed particles was evaluated, The SEM images demonstrate the effectiveness of the ultrasonic atomizer spraying procedure in the disaggregation nanoparticles, as seen by the reduced mean particle size in the sprayed layer compared to the as prepared powder. Finally, this study suggest that the dispersion process of photoluminescent nanoparticles on a substrate holds the potential for optical traceability.

Numerical analysis of multistage ultrasonic atomization enhanced ammonia-water falling film absorption

The absorption refrigeration system is a widely used system that utilizes waste heat and is environmentally friendly. However, many current systems still suffer from challenges such as large volume, and high initial investment. Meanwhile, optimizing the absorber is crucial for enhancing system performance as it is one of the main components. In this study, a novel absorber model is proposed and its influencing factors of performance are comprehensively analyzed. In this model, the traditional falling film absorber is divided into multiple stages, with an ultrasonic atomizer (UA) installed in each stage to enhance absorption. In each stage, falling film and atomization absorption occur simultaneously, and their outputs are combined and weighted at the exit to maintain continuous droplet absorption, effectively utilizing the entire absorber volume. In this process, the vapor–liquid contact area is increased through atomization, and simultaneously, generated heat is removed by the cooling water during mixing. As a result, the absorber’s absorption capacity increases, and the outlet solution temperature decreases. The results demonstrate that compared to the traditional falling film absorber, the proposed absorber, when divided into two stages with a droplet diameter of 50 μm and an atomization rate x = 0.7, shows a 60.64 % increase in ammonia absorbed rate. Additionally, compared to double-stage absorber, triple-stage absorber increases the ammonia absorption by 9.52 %. As the number of stages increased, the strengthening effect persisted, albeit with a gradually diminishing rate of increase. Scaling up to ten stages results in a 152.63 % absorption rate increase and a size optimization of 60.43 %. In this paper, multi-stage ultrasonic atomization is innovatively introduced into the falling film absorber, which enhances ammonia absorption and reduces the volume of the absorber. Additionally, the multi-stage atomization offers an innovative method to improve the droplet absorption process.

High-precision ultrasonic atomization using oscillating microchannels: Interplay of three-dimensional vibrational modes and droplet ejection mechanisms

Ultrasonic atomization is a critical process for producing micrometer-diameter droplets, widely utilized in aerosol drug delivery, spectrometry, and printing. The geometry of the vessel containing the fluid being atomized and the oscillations of its sidewalls play a crucial role in controlling the wave patterns and hence the droplet ejection process, especially at actuation frequencies exceeding 1 MHz. However, the mechanisms behind droplet ejection under high-frequency ultrasonic actuation remain poorly understood. We employ oscillating high-aspect-ratio Silicon microchannels to create ideal conditions where capillary forces, microchannel geometry, and oscillatory motion work together to precisely confine a liquid film and generate droplets with controlled diameters. We show that the three-dimensional vibrations of the microchannels, particularly the interplay between actuation frequency, amplitude, and channel geometry, can be used to effectively tune the ligament development and droplet breakup. This understanding allows us to establish conditions to reduce actuation power and hence minimize heating, control shear stresses and tune the droplet size on-demand without compromising uniformity and throughput.

Impact of Chemical Composition Changes during Ultrasound Atomization and Laser Powder Bed Fusion of Low Alloy Steel

This study investigates the effect of changing the chemical composition during ultrasonic atomization (UA) and laser powder bed fusion (LPBF) of low‐alloy steel. UA is used to produce a spherical powder with d50 equal to 49 μm. During UA, the chemical composition of the material changes, which is associated with selective evaporation of Mn from 1.42% to 0.35% and B from 0.0012% to &lt;0.0001%. Thermodynamic calculations confirm that during atomization, mostly Mn and Fe evaporate. To achieve a high density of 3D printed parts, in situ remelting in LPBF is applied. A microstructure consisting of fine grains of tempered martensite and bainite in crystallized meltpools is observed. The selected high‐quality LPBF samples are austenitized in the temperature range of 900–1200 °C for 20 min and quenched in oil. The samples are characterized by light and scanning electron microscopy, as well as Vickers hardness. Changes in chemical composition result in a decrease in the hardenability of the material, and quenching only at 1200 °C produces a martensitic microstructure. LPBF samples show a hardness higher than that of the postheat‐treated sample, but still significantly lower than that of the as‐delivery condition, which is related to the change in chemical composition.

Ultrasonic atomization technique for enhancing humidification process in thermal desalination

The need for desalination is expected to evolve, and interests in novel techniques to enhance thermal desalination are developing. Research studies on ultrasonic atomization for desalination application has been observed in the last few years. Hence, this study aims to examine humidification process enhancement using ultrasonic atomization and interaction of atomized droplets with hot air in the humidifier. In the Humidification and Dehumidification (HDH) desalination system examined, the humidifier is equipped with a single ultrasonic atomizer unit which operates continuously with preheated hot air entering the humidifier chamber. The system is investigated for different air flowrates (40 – 100 LPM) and hot air temperatures (40, 50, and 60 °C). The average relative humidity at the humidifier outlet was maximum reaching 94 % for the highest flowrate. The results indicate that increasing hot air temperatures have significant improvement in droplet evaporation which causes higher relative humidity at the outlet, and increasing hot air flowrates have significant impact on the faster response of the humidification process to reach equilibrium.

Enhanced TiO2-Based Photocatalytic Volatile Organic Compound Decomposition Combined with Ultrasonic Atomization in the Co-Presence of Carbon Black and Heavy Metal Nanoparticles.

Volatile organic compounds (VOCs) are representative indoor air pollutants that negatively affect the human body owing to their toxicity. One of the most promising methods for VOC removal is photocatalytic degradation using TiO2. In this study, the addition of carbon black (CB) and heavy metal nanoparticles (NPs) was investigated to improve the efficiency of a TiO2-based photocatalytic VOC decomposition system combined with ultrasonic atomization and ultraviolet irradiation, as described previously. The addition of CB and Ag NPs significantly improved the degradation efficiency. A comparison with other heavy metal nanoparticles and their respective roles are discussed.

Crack-Resistant Si-C Hybrid Microspheres for High-Performance Lithium-Ion Battery Anodes.

To effectively solve the challenges of rapid capacity decay and electrode crushing of silicon-carbon (Si-C) anodes, it is crucial to carefully optimize the structure of Si-C active materials and enhance their electron/ion transport dynamic in the electrode. Herein, a unique hybrid structure microsphere of Si/C/CNTs/Cu with surface wrinkles is prepared through a simple ultrasonic atomization pyrolysis and calcination method. Low-cost nanoscale Si waste is embedded into the pyrolysis carbon matrix, cleverly combined with the flexible electrical conductivity carbon nanotubes (CNTs) and copper (Cu) particles, enhancing both the crack resistance and transport kinetics of the entire electrode material. Remarkably, as a lithium-ion battery anode, the fabricated Si/C/CNTs/Cu electrode exhibits stable cycling for up to 2300 cycles even at a current of 2.0 A g-1, retaining a capacity of ≈700 mAh g-1, with a retention rate of 100% compared to the cycling started at a current of 2.0 A g-1. Additionally, when paired with an NCM523 cathode, the full cell exhibits a capacity of 135 mAh g-1 after 100 cycles at 1.0C. Therefore, this synthesis strategy provides insights into the design of long-life, practical anode electrode materials with micro/nano-spherical hybrid structures.

Effect of wettability on paper literature deacidification by ultrasonic atomization

Effect of wettability on paper literature deacidification by ultrasonic atomization

Assessment of thermoeconomic and thermoenvironmental impacts of a novel solar desalination system using a heat pump, evacuated tubes, cover cooling, and ultrasonic mist

Various desalination methods have been introduced to address the growing demand for freshwater. Among these methods, solar stills have emerged as one of the simplest approaches. However, their performance has been hindered by low reliability, particularly due to heavy reliance on solar energy year-round. Addressing this issue, this study presents a novel and reliable solar desalination unit incorporating an evacuated tube water solar heater as a heat collector and a 250 W heat pump unit for condensation. Additionally, ultrasonic atomizers are integrated to facilitate vapor generation and accelerate its separation from the hot water fed into the desalination unit. The research commences with the selection of the optimal number of atomizers, followed by a comprehensive analysis encompassing environmental, economic, exergy, and energy (4E) considerations for the system with the optimal atomizer configuration. Furthermore, cover cooling is implemented to enhance condensation rates. Results indicate that the system, equipped with a single atomizer, yields 19.565 L/m2 per day of distilled water, with daily energy and exergy efficiencies of 62.39 % and 6.04 %, respectively. Following cover cooling, the system achieves production of 20.95 L/m2 of distilled water per day, accompanied by energy and exergy efficiencies of 65.48 % and 6.67 %, respectively. These improvements represent enhancements in freshwater production, energy efficiency, and exergy efficiency by 431.7 %, 57.82 %, and 74.61 %, respectively. Additionally, the system demonstrates a cost reduction of 14.36 % and a decrease in carbon dioxide emissions by 11.17 tons CO2, underscoring its economic and environmental benefits.

Comprehensive analysis of ultrasonically atomized 316L stainless steel powder using adjusted additive manufacturing suitability factor

This study focuses on the 316L stainless steel powder produced by using an innovative ultrasonic atomization (UA) method. The production process was optimized at electrical currents with 120 A and vibration amplitude with 80% proving the most effective for maximizing productivity. The study extensively evaluated particle size and shape, bulk and tapped densities, Hausner's ratio, and Carr index, finding the UA steel powder to possess high sphericity, minimal satellite particles, and excellent flowability, qualities crucial for additive manufacturing (AM). A new approach for calculating the additive manufacturing suitability factor was developed, incorporating custom weighting factors for rheological parameters to reduce the influence of parameters with high uncertainty or statistical insignificance, thus improving accuracy. When compared using this method, the UA powder demonstrated superiority over its commercial counterparts by approximately 1% and 10%, underscoring its promise for AM applications.

Remote-Controlled Sensing and Drug Delivery via 3D-Printed Hollow Microneedles.

Remote health monitoring and treatment serve as critical drivers for advancing health equity, bridging geographical and socioeconomic disparities, ensuring equitable access to quality healthcare for those in underserved or remote regions. By democratizing healthcare, this approach offers timely interventions, continuous monitoring, and personalized care independent of one's location or socioeconomic status, thereby striving for an equitable distribution of health resources and outcomes. Meanwhile, microneedle arrays (MNAs), revolutionize painless and minimally invasive access to interstitial fluid for drug delivery and diagnostics. This paper introduces an integrated theranostic MNA system employing an array of colorimetric sensors to quantitatively measure -pH, glucose, and lactate, alongside a remotely-triggered system enabling on-demand drug delivery. Integration of an ultrasonic atomizer streamlines the drug delivery, facilitating rapid, pumpless, and point-of-care drug delivery, enhancing system portability while reducing complexities. An accompanying smartphone application interfaces the sensing and drug delivery components. Demonstrated capabilities include detecting pH (3 to 8), glucose (up to 16mm), and lactate (up to 1.6mm), showcasing on-demand drug delivery, and assessing delivery system performance via a scratch assay. This innovative approach confronts drug delivery challenges, particularly in managing chronic diseases requiring long-term treatment, while also offering avenues for non-invasive health monitoring through microneedle-based sensors.