Device, method and substance for detection of adulteration in liquids

Abstract

The present invention relates to the technical field of surface science and nanotechnology for detecting adulterants in liquids including milk. More particularly, the present invention relates to a superhydrophobic surface, device and method for detecting adulterants in liquids including milk by utilization of a superhydrophobic surface.

Description

[0001] DEVICE, METHOD AND SUBSTANCE FOR DETECTION OF ADULTERATION IN LIQUIDS

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the technical field of surface science and nanotechnology for detecting adulterants in liquids including milk. More particularly, the present invention relates to a superhydrophobic surface, device and method for detecting adulterants in liquids including milk by utilization of a superhydrophobic surface.

[0004] BACKGROUND OF THE INVENTION

[0005] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention.

[0006] Milk is an essential dietary component, rich in nutrients and vital for overall human health. In India, where milk consumption is widespread and deeply ingrained in the daily diet, ensuring the purity and quality of milk is of paramount importance. However, the adulteration of milk has emerged as a significant concern, threatening public health and consumer confidence. Unscrupulous practices of milk adulteration involve mixing water, synthetic chemicals, and other substances to increase volume and profit margins, while compromising the nutritional value of milk. To combat this issue effectively, the development and application of advanced and accessible techniques for milk adulteration detection are critical.

[0007] This sub-section delves into the significance of milk adulteration in India and the potential use of the present innovation to detect adulteration in milk. Milk adulteration in India is a pressing issue that impacts millions of consumers daily. The adulteration practices not only jeopardize public health but also undermine the efforts to provide wholesome and nutritious food to the population. Common adulterants, such as water, urea, detergent, starch, and caustic soda, have been detected in milk samples across various regions, posing severe health hazards, particularly for vulnerable groups such as infants, children, and the elderly. Adulterated milk consumption has been linked to gastrointestinal disorders, food poisoning, and long-term health implications due to exposure to harmful chemicals. Moreover, the economic impact of adulteration is significant, as consumers unknowingly pay for diluted or inferior quality milk, while genuine dairy farmers suffer losses due to unfair competition. Thus, ensuring the purity and authenticity of milk is crucial for promoting public health, consumer rights, and the growth of the dairy industry in India.

[0008] Various prior arts are known relating to the milk adulteration detection devices in market, for instance, reference can be made to PCT application, WO2015132648A2 which discloses a rapid detection method for identifying milk adulterant by using the test strips that may optionally attached to a substrate, wherein, i) at least one test strip is capable of converting a first adulterant to oxygen; ii) at least one test strip is capable of converting a second adulterant to ammonia gas; iii) at least one test strip is capable of detecting adulterants selected from urea, sulphate ions, alkalinity, formalin, detergent, starch, or nitrate ions.

[0009] Further reference can be made to US20140065712A1, which discloses a system for detecting an adulterant in a sample of milk by using a cotton thread based microfluidic system.

[0010] However, current milk adulterant detection methods face complexities requiring specialized techniques and have limited scope of utilisation, due to diverse adulterants, demanding high sensitivity, and the heterogeneous composition of milk. Current methods require specialized techniques, considering factors like:

[0011] 1. Adulterant Diversity: Varied substances demand distinct detection methods.

[0012] 2. Sensitivity and Specificity: High sensitivity and specificity are crucial to avoid false results.

[0013] 3. Sample Complexity: Milk's complex composition interferes with detection accuracy.

[0014] 4. Rapid Detection: Quick, on-the-spot detection methods are vital in the dairy industry.

[0015] 5. Regulatory Compliance: Compliance with regulatory standards is challenging.

[0016] 6. Complex Instruments: Some methods use sophisticated instruments, requiring skilled operators and high costs.

[0017] 7. Interference and Masking: Interference between adulterants may lead to inaccurate results.

[0018] 8. Multidisciplinary Approach: Effective detection involves collaboration across disciplines.

[0019] Further, milk is distributed in various locations, including remote rural areas, wherein, sophisticated laboratory equipment may not be available. Portable, field-friendly detection methods are required to cater to such situations. Various milk adulterants and its detection method are known in the literature, as can be seen from the list below in Table 1.

[0020] Table 1. List of few of the popular milk adulterants and its detection methods

[0021] Furthermore, the conventional milk adulterant detection methods and devices face complexities due to diverse adulterants, demanding high sensitivity, and the heterogeneous composition of milk. Thus, prior arts for the detection of adulteration are known, however, the prior arts have several demerits like high cost, complex instrumentation and in some of them detection procedure is complicated.

[0022] Therefore, there is a need of for novel device and system for overcoming abovementioned problems. There is a high need of a low cost, portable, point-of-use, efficient detection device and method for monitoring the adulterants and determination of adulteration. OBJECTS OF THE INVENTION

[0023] The principal object of this invention is to provide a simple, cost effective superhydrophobic surface for detection of adulterants present in a liquid-droplet, in particular adulterants in milk. Another object of this invention is to provide a simple, cost effective and point of use of effective sensory system for detection of adulterants in milk.

[0024] A further object of this invention is to provide a superhydrophobic aluminium surface that serves as a substrate for the effective sensory system, enabling it to detect changes in contact angle caused by the presence of milk and its adulterants.

[0025] A further object of this invention is to provide a device and method for detecting adulterants in liquid droplet, preferably milk by utilizing a sensory system based on surface science and nanotechnology.

[0026] A further object of this invention is to provide a device and method for detecting adulterants in milk by utilizing a sensory system based on wettability mechanisms.

[0027] A further object of this invention is to provide a device which utilises simple electronic components and sensory system based on wettability mechanisms to measure alterations in the wetting characteristics / behaviours of liquid droplets on a superhydrophobic surfaces.

[0028] A further object of this invention is to provide a device and method for detecting adulterants in milk involving superhydrophobic surface, wherein, the super-hydrophobic surface is a super-hydrophobic aluminium surface.

[0029] A further object of this invention is to provide a device and method for detecting adulterants in liquid droplet, preferably milk by analysing changes or alteration in the resistance caused by the liquid droplet on the super hydrophobic aluminium surfaces.

[0030] A further object of this invention is to provide a device and method for measuring and analysing changes or alteration in the wetting characteristics / behaviour of liquid droplets utilizing superhydrophobic aluminium surfaces. Yet one another objective of the present invention is to provide a device and method for detecting milk adulterants by measuring and analysing changes in the wetting behaviour of liquid droplets utilizing a super-hydrophobic surface.

[0031] A further object of this invention is to provide a device and method for detecting various adulterants in liquid droplet including water, maltodextrin, ammonium sulphate, sodium hydroxide, sodium bicarbonate, sodium chloride, formalin, starch, detergents, vegetable oils, synthetic chemicals, sodium salicylate, ammonium sulphate, dextrose, hydrogen peroxide, cane sugar, nitrates, sulfates, detergents, neutralizers, or combination thereof.

[0032] A further object of this invention is to provide a device and method for detecting adulterants in a liquid droplet, preferably milk adulterants in real-time capability, enabling quick analysis and immediate results.

[0033] A further object of this invention is to provide a device and for detecting milk adulterants which requires minimal user training and is cost effective.

[0034] Another object of this invention is to provide a development and application of a device for detecting adulterants in milk.

[0035] Another object of this invention is to provide a practical and efficient solution for precisely measuring and analysing changes in the wetting behaviour of liquid droplets, specifically in the context of milk adulteration.

[0036] ADVANTAGES OF THE PRESENT INVENTION:

[0037] The present invention offers following advantages:

[0038] • The present invention offers a valuable tool for quality control and ensuring the authenticity of milk products.

[0039] • The present invention is user-friendly, cost-effective and have real-time capability which make it accessible to researchers, industries, and practitioners across various scientific and technological fields for detection of adulterants. • The present invention offers a practical and efficient solution which helps in regulatory compliance, promote transparency, and safeguard consumer health and trust within the dairy industry.

[0040] • The present invention offers the device which operates which is simple to assemble and requires minimal user training, it can be deployed at various levels of the milk supply chain, from dairy farms to retail outlets, to ensure on-the-spot adulteration screening.

[0041] SUMMARY OF THE INVENTION

[0042] Accordingly, the present invention provides a device and method for detection of adulterants in a liquid droplet, preferably milk adulterants by utilizing a superhydrophobic surfaces. More specifically, the present invention utilizes a superhydrophobic aluminium surface, provides a method for quantitatively assessing and interpreting modifications in the wetting characteristics caused by adulterants in a liquid droplet, preferably milk adulterants.

[0043] In an aspect, the present invention provides a superhydrophobic surfaces for the detection of an unauthorized substances / adulterants of a liquid-droplet, characterized in that, the superhydrophobic surfaces are established on an aluminium alloy-based substrate having a chemical composition comprising: i) 4.0-6.5 wt % Mg, ii) 0.3 wt % Si, iii) 0.1-0.5 wt % Fe, iv) 0.5-0.9 wt % Mn, v) 0.23 wt % Zn, vi) 0.2 wt % Cu, vii)0.14 wt % Ti, viii) 0.04-0.26 wt % Cr, and ix) the balance is Al.

[0044] In another aspect, the present invention provides that the substrate is fabricated by friction stir processing (FSP), stationery friction processing (SFP), hot -water treatment, and abrasive machining.

[0045] In another aspect, the present invention provides that the unauthorized substances / adulterants are detected by measuring the alteration in the wetting characteristics / behaviour of an adulterants. In another aspect, the present invention provides that the wetting characteristics / behavior of an adulterants are measured by change in contact angle across a superhydrophobic surfaces caused by the presence of unauthorized substances / adulterants in liquid-droplet.

[0046] In an aspect, the present invention provides that the present invention provides a device for the detection of an unauthorized substances / adulterants in a liquid-droplet, comprises: a) a substrate; and b) integrated electronic components, wherein, the substrate is fabricated by the superhydrophobic aluminum surface and the device detects the unauthorized substances / adulterants by measuring the wetting characteristics / behavior of adulterants measured by the change in contact angle across the superhydrophobic surfaces.

[0047] In another aspect, the present invention provides that the change in contact angle across the superhydrophobic surfaces is caused by the presence of unauthorized substances / adulterants in liquid-droplet by an innovative sensing technique based on the detection of changes in resistance caused by the liquid droplet on the superhydrophobic surfaces.

[0048] In another aspect, the present invention provides that the integrated electronic components comprise: i) a microcontroller, ii) LCD display, and iii) an integrated sensor.

[0049] In another aspect, the present invention provides that the device operates by emitting infrared light from the IR LED sensor onto the superhydrophobic substrate, and the photodiode detects changes in resistance caused by the liquid droplet on the superhydrophobic aluminum surfaces.

[0050] In another aspect, the present invention provides that the device works on Arduino programming.

[0051] In yet another aspect, the present invention provides that the present invention provides a device for the detection of milk adulterants, comprises: a) a superhydrophobic aluminum surfaces; and b) integrated electronic components, wherein, the device detects the unauthorized substances / adulterants by measuring the wetting characteristics / behavior of adulterants measured by change in contact angle across a superhydrophobic surfaces caused by the presence of unauthorized substances / adulterants in liquiddroplet, with innovative sensing technique based on the detection of changes in resistance caused by the liquid droplet on the superhydrophobic surfaces.

[0052] In yet another aspect, the present invention provides that the present invention provides a method for the detection of an unauthorized substances / adulterants of a liquid-droplet, the method comprises: a) identification of adulterants by placing liquid droplet on the superhydrophobic surfaces, b) the change in resistance observed by the photodiode, caused by the interaction of light with the adulterated liquid-droplet, will be processed by the microcontroller and displayed as a digital value on the LCD screen. wherein, the unauthorized substances / adulterants are detected by measuring the wetting characteristics / behavior of an adulterants.

[0053] In another aspect, the present invention provides that the method is for the detection of adulteration of milk.

[0054] In an aspect, the present invention provides a superhydrophobic aluminium surface that serves as a substrate for the effective sensory system, enabling it to detect changes in contact angle caused by the presence of milk and its adulterants.

[0055] In an aspect, the present invention provides a superhydrophobic surface for the detection of an unauthorized substances / adulterants of a liquid-droplet, characterized in that, the unauthorized substances / adulterants are detected by measuring the alteration in the wetting characteristics / behavior of an adulterants.

[0056] In another aspect, the liquid droplet is milk or milk adulterants, honey, soy milk, almond milk, coconut milk, mustard oil, palm oil, sunflower oil, soyabean oil, olive oil, coconut oil, groundnut oil, sesame oil, rice bran oil, or combination thereof.

[0057] In another aspect, the wetting characteristics / behavior of an adulterants are detected by change in contact angle across a superhydrophobic surface caused by the presence of unauthorized substances / adulterants in liquid-droplet. In an aspect, the microcontroller serves as a control unit, processing signals from the sensors and executing the wetting detection algorithm.

[0058] In an aspect, the LCD display provides a user-friendly interface, displaying the results obtained from the wetting detection process in real-time.

[0059] In an aspect, the photodiode sensor, acts as a light receiver, detects the light without any substantial change in resistance.

[0060] In an aspect, the IR LED sensor emits infrared light, which is directed towards the superhydrophobic aluminum surfaces, and the liquid droplet placed between the photodiode sensor and IR LED sensor.

[0061] In an aspect, the device operates by emitting infrared light from the IR LED sensor onto the superhydrophobic substrate, and the photodiode detects changes in resistance caused by the liquid droplet on the superhydrophobic aluminum surface.

[0062] In an aspect, the device comprises Arduino programming to detect adulterants.

[0063] In an aspect, the present invention provides a device for detection of adulterants in milk comprising: a) Battery source, wherein a battery acts as the power supply for the device, providing the necessary electrical energy to power the electronic components; b) Sensors, wherein the device integrates two sensors a photodiode sensor and Infrared LED (IR LED) sensor, which work together to measure changes in resistance caused by the liquid droplet on the superhydrophobic substrate; c) Microcontroller unit, wherein said microcontroller provisioned to provide processing signals from the sensors and executing the wetting detection algorithm; d) LCD Display serves as the user interface, displaying the results obtained from the wetting detection process; e) Voltage regulator, wherein voltage regulator is integrated into the circuit to stabilize the voltage output and ensure a constant supply for the microcontroller and other components; f) Potentiometer, is used to adjust the sensitivity or threshold of the device. It allows the user to control the detection range for different wetting behaviours; g) Resistors, two resistors are used in the circuit, which are essential for proper voltage division and current limiting; h) Super-hydrophobic substrate, wherein the milk sample is placed on the super-hydrophobic substrate; wherein the device is constructed on a printed circuit board (PCB) to ensure a neat and organized arrangement of the electronic components.

[0064] In an aspect, the present invention, provides a method for quantitatively assessing and interpreting modifications in the wetting characteristics of caused by adulterants in milk or liquid droplet adulterants.

[0065] In an aspect, the present invention provides a method for detection of adulterants in milk by utilizing a superhydrophobic aluminium surfaces, comprising the steps of:

[0066] • Photodiode Detection: In the absence of a liquid droplet on the superhydrophobic aluminium surface, the infrared light from the Sensors specifically, IR LED passes through the substrate without any significant hindrance. The photodiode, acting as a light receiver, detects the light without any substantial change in resistance.

[0067] • Wetting Detection: In the presence of a liquid droplet, it wets the superhydrophobic aluminium surfaces, it alters the path of the infrared light passing through it. The presence of the liquid droplet causes a change in the light intensity received by the photodiode, leading to a change in resistance in the photodiode circuit.

[0068] • Voltage Division: The photodiode's resistance change is converted into a voltage signal through the voltage division provided by the lOkQ resistor and the photodiode's resistance. This voltage signal is fed to the microcontroller's analogue input pin (Pin 3) through the potentiometer.

[0069] • Microcontroller Processing: The microcontroller continuously monitors the voltage signal from the photodiode and processes it. It compares the voltage value with a predefined threshold (13) set by the potentiometer, which determines the wetting detection sensitivity.

[0070] • LCD Display: Based on the comparison result, the microcontroller determines the wetting behaviour of the liquid droplet and displays the corresponding status on the display. The LCD provides a real-time indication of the wetting characteristics of the liquid droplet on the substrate.

[0071] In an aspect, the present invention provides that to generate the Arduino code for this device with the specified components, the Arduino IDE (Arduino Integrated Development Environment) has been used.

[0072] In an aspect, the present invention provides a development and application of a device for detecting adulterants in milk. In an aspect, the present invention provides a practical and efficient solution for precisely measuring and analysing changes in the wetting behaviour of liquid droplets, specifically in the context of milk adulteration.

[0073] In an aspect, the present invention provides a user-friendly, cost-effectiveness, and real-time capability device that make it accessible to researchers, industries, and practitioners across various scientific and technological fields. It can be utilized in both laboratory and field settings, catering to the needs of various users, including households and laboratories. The device's simplicity, portability, and minimal maintenance requirements make it feasible for widespread implementation, including in resource-constrained settings and remote rural areas.

[0074] BRIEF DESCRIPTION OF DRAWINGS

[0075] To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings in which:

[0076] Figure 1(a): illustrates schematic representation of construction of device.

[0077] Figure 1(b): illustrates wetting detection representation and mechanism of working of device.

[0078] Figure 2: illustrates Circuit diagram of the device.

[0079] Figure 3: illustrates effect of Maltodextrin adulteration w.r.t (a) contact angle (b) surface tension (c). Figure 4: illustrates Digital value output on the device with Pure and Maltodextrin samples.

[0080] Figure 5: illustrates effect of Ammonium sulphate adulteration w.r.t (a) contact angle (b) surface tension (c) the device output values.

[0081] Figure 6: illustrates digital value output on the device with Pure and Ammonium sulphate samples Figure 7: illustrates effect of Sodium hydroxide adulteration w.r.t (a) contact angle (b) surface tension (c) device output values.

[0082] Figure 8: illustrates digital value output on the device with Pure and Sodium hydroxide samples.

[0083] Figure 9: Effect of Sodium bicarbonate adulteration w.r.t (a) contact angle (b) surface tension (c) the device output values; Error bars indicate the standard deviation across multiple samples.

[0084] Figure 10: illustrates digital value output on the device with Pure and Sodium bicarbonate samples. Figure 11 : illustrates Effect of Sodium chloride adulteration w.r.t (a) contact angle (b) surface tension (c) the device output values; Error bars indicate the standard deviation across multiple samples.

[0085] Figure 12: Digital value output on the device with Pure and Sodium chloride samples.

[0086] Figure 13: Effect of Water adulteration w.r.t (a) contact angle (b) surface tension (c) the device output values; Error bars indicate the standard deviation across multiple samples.

[0087] Figure 14: illustrates: digital value output on the device with Pure and Water samples.

[0088] DETAILED DESCRIPTION OF THE INVENTION

[0089] In describing the embodiments of the invention, specific terminology is resorted for sake of clarity. However, it is not intended that the invention be limited to specific terms so selected and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

[0090] For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

[0091] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof. Throughout the patent specification, a convention employed is that in the appended drawings, like numerals denote like components.

[0092] In an embodiment, the present invention provides a superhydrophobic surface for the detection of an unauthorized substances / adulterants of a liquid-droplet, characterized in that, the superhydrophobic surfaces are established on an aluminium alloy-based substrate having a chemical composition comprising: i) 4.0-6.5 wt % Mg, ii) 0.3 wt % Si, iii) 0.1-0.5 wt % Fe, iv) 0.5-0.9 wt % Mn, v) 0.23 wt % Zn, vi) 0.2 wt % Cu, vii)0.14 wt % Ti, viii) 0.04-0.26 wt % Cr, and ix) the balance is Al.

[0093] In an embodiment, the substrate is fabricated by friction stir processing (FSP), stationery friction processing (SFP), hot-water treatment, and abrasive machining.

[0094] In an embodiment, the unauthorized substances / adulterants are detected by measuring the alteration in the wetting characteristics / behaviour of an adulterants.

[0095] In an embodiment, the superhydrophobic surfaces is a superhydrophobic aluminum surface.

[0096] In an embodiment, the liquid droplet is milk or milk adulterants, honey, soy milk, almond milk, coconut milk, mustard oil, palm oil, sunflower oil, soyabean oil, olive oil, coconut oil, groundnut oil, sesame oil, rice bran oil, or combination thereof.

[0097] In an embodiment, unauthorized substances / adulterants are selected from the group comprising of water, maltodextrin, urea / ammonium sulphate, caustic soda / sodium hydroxide, sodium bicarbonate, sodium chloride, formalin, starch, detergents, vegetable oils, synthetic chemicals, sodium salicylate, ammonium sulphate, dextrose, hydrogen peroxide, cane sugar, nitrates, sulfates, detergents, neutralizers, or combination thereof.

[0098] In an embodiment, the wetting characteristics / behavior of an adulterants are measured by change in contact angle across a superhydrophobic surfaces caused by the presence of unauthorized substances / adulterants in liquid-droplet.

[0099] In an embodiment, the change in contact angle is attributed by change in the electrical resistance across the superhydrophobic surfaces.

[0100] In yet another embodiment, the present invention provides a device for the detection of an unauthorized substances / adulterants in a liquid-droplet, comprises: c) a substrate; and d) integrated electronic components, wherein, the substrate is fabricated by the superhydrophobic aluminum surface and the device detects the unauthorized substances / adulterants by measuring the wetting characteristics / behavior of adulterants measured by the change in contact angle across the superhydrophobic surfaces.

[0101] In one of the embodiments, the change in contact angle across the superhydrophobic surfaces is caused by the presence of unauthorized substances / adulterants in liquid-droplet by an innovative sensing technique based on the detection of changes in resistance caused by the liquid droplet on the superhydrophobic surfaces.

[0102] In one of the embodiments, the integrated electronic components comprise: i) a microcontroller, ii) LCD display, and iii) an integrated sensor.

[0103] In one of the embodiments, the integrated sensor comprises a photodiode sensor, and an IR LED sensor.

[0104] In one of the embodiments, the microcontroller serves as a control unit, processing signals from the sensors and executing the wetting detection algorithm.

[0105] In one of the embodiments, the LCD display provides a user-friendly interface, displaying the results obtained from the wetting detection process in real-time.

[0106] In one of the embodiments, the photodiode sensor, acts as a light receiver, detects the light without any substantial change in resistance.

[0107] In one of the embodiments, the IR LED sensor emits infrared light, which is directed towards the superhydrophobic aluminum surface, and the liquid droplet placed between the photodiode sensor and IR LED sensor.

[0108] In one of the embodiments, the device operates by emitting infrared light from the IR LED sensor onto the superhydrophobic substrate, and the photodiode detects changes in resistance caused by the liquid droplet on the superhydrophobic aluminum surfaces.

[0109] In one of the embodiments, the device works on Arduino programming.

[0110] In one of the embodiments, the device further comprises a battery source, a voltage regulator, a potentiometer and resistors. In one of the embodiments, the device is constructed on a printed circuit board (PCB).

[0111] In one of the embodiments, the device is for the detection of the adulterant of the following milk, honey, soy milk, almond milk, coconut milk, mustard oil, palm oil, sunflower oil, soyabean oil, olive oil, coconut oil, groundnut oil, sesame oil, rice bran oil, or combination thereof.

[0112] In another embodiment, the present invention provides a device for the detection of milk adulterants, comprises: a) a superhydrophobic aluminum surfaces; and b) integrated electronic components, wherein, the device detects the unauthorized substances / adulterants by measuring the wetting characteristics / behavior of adulterants measured by change in contact angle across a superhydrophobic surfaces caused by the presence of unauthorized substances / adulterants in liquiddroplet, with innovative sensing technique based on the detection of changes in resistance caused by the liquid droplet on the superhydrophobic surfaces.

[0113] In yet another embodiment, the present invention provides a method for the detection of an unauthorized substances / adulterants of a liquid-droplet, the method comprises: a) identification of adulterants by placing liquid droplet on the superhydrophobic surfaces, b) the change in resistance observed by the photodiode, caused by the interaction of light with the adulterated liquid-droplet, will be processed by the microcontroller and displayed as a digital value on the LCD screen. wherein, the unauthorized substances / adulterants are detected by measuring the wetting characteristics / behavior of an adulterants.

[0114] In one of the embodiments, the method is for the detection of adulteration of milk.

[0115] In another embodiment, the superhydrophobic surfaces are capable of repelling liquid droplets. The substrate of the present invention is made from the most common metal, aluminium, and is converted into a superhydrophobic surface by fabrication. Initially, the substrate is in a hydrophilic state (i.e., Contact angle -80°). The liquid droplets can easily roll off this surface due to a wide range of surfaces with different surface tension, including milk with a surface tension of 58 N / m and other liquid droplets ranging from 28 to 72 N / m.

[0116] In another embodiment, the present invention provides that an aluminium alloy (AA5083) plates / substrate of commercial grade (ASTM-B-209M) is utilized having a chemical composition comprising: 4.0-6.5 wt % Mg, 0.3 wt % Si, 0.1-0.5 wt % Fe, 0.5-0.9 wt % Mn, 0.23 wt % Zn, 0.2 wt % Cu, 0.14 wt % Ti, 0.04-0.26 wt % Cr and the balance was Al.

[0117] In one of the embodiments, the present invention provides that before further processing, the plates / substrates are cleaned and degreased with acetone (99.9%) and rinsed with Deionized (DI) water. Friction stir processing (FSP) is performed on a universal milling machine, wherein, as a part of the process for the fabrication, a non -consumable rotating tool is used with a specially designed pin-less mild steel tool of 12 mm shoulder diameter that is used to focus only on the surface properties of the aluminium alloy at a constant transverse speed of 20 mm / min along the line of the process. During FSP, the material in the processed zone is subjected to intense plastic deformation, mixing, and thermal exposure, resulting in significant changes to its microstructure. FSP is used to fabricate a superhydrophobic aluminium substrate. The change in microstructure is caused by the FSP and SFP processes for the aluminium alloy plates.

[0118] In one of the embodiments, the processed zone is characterized by a fine-grained structure that has been recrystallized and is uniformly distributed with particles from the second phase, i.e., the tool serves two primary functions: (a) heating the workpiece, and (b) moving material to refine it. A heat source is achieved by friction between the tool and the workpiece, in combination with plastic deformation of the workpiece. This workpiece is made from mild steel, one of the most cost-effective metals, and one that is readily available and has excellent machineability. Localized heating softens the material around the tool, and the combination of rotation and travel causes the material to move from one place to another.

[0119] Simultaneously, stationery friction processing (SFP) is also performed under similar conditions without translation of the tool. The rotational speed of 288 rpm for processing of samples utilizing FSP and SFP at a plunge depth of 0.4 mm. After processing, samples with dimensions of 10 mm x 10 mm x 5 mm were prepared using an abrasive cut-off machine.

[0120] In an embodiment, the prepared samples are further polished with abrasive papers down to 1000 grit. The microwave hot water treatment (mHWT) of the processed and unprocessed samples are performed in a multimode microwave cavity at 800 W (Samsung MS23L) for 10 min, during which the water temperature was measured to be 100 °C. After mHWT, the samples were thoroughly dried for 60 min at a temperature of 55 °C.

[0121] In an embodiment, the surface morphology of the samples is observed under field emission scanning electron microscopy (FESEM) (JEOL, JSM-7610FPlus) equipped with energy dispersive spectroscopy (EDS). Atomic force microscope (AFM) (XE7, Park Systems) is also used to evaluate the morphology of the samples at the nanoscale, with scan areas of 2 x 2 pm2, 10 x 10 pm2and 15 x 15 pm2.

[0122] Further, the SPM (Scanning Probe Microscope) Software, is used to calculate the surface topological calculations in a micro-nano surface of any substrate. This is utilized to calculate the average nanoscale roughness and roughness factor. A Fourier-transform infrared spectrometer (FTIR) (Thermo Fisher Scientific, USA) equipped with an attenuated total reflectance diamond crystal is utilized to analyze the surface chemistry of the samples. The spectra in the range of 400-4000 cm1is obtained, and the data is processed involving OMNIC software (Thermo Fisher Scientific, USA). OMNIC software is used to analyze Fourier Transform Infrared Spectra for substrates. T he grain size and distribution for all specimens is obtained using the electron backscatter diffraction (EBSD) technique (FEI Quanta 3D FEG) utilizing a step size of 0.1 pm.

[0123] In an embodiment, the synthesized nanostructures' chemical composition was confirmed using X-ray photoelectron spectroscopy (XPS) utilizing a monochromatic Al- / <a radiation source (1.486 keV, Scientia Omicron Nanotechnology). The obtained spectra were de -convoluted and analyzed using CasaXPS (V2.3) software. The wetting behaviour of the samples was evaluated by quantifying static (9S), advancing (0a), receding (0r), and tilt angles (0£) using a contact angle goniometer (Apex Instruments, India) with a sessile drop method. Static contact angle measurements is performed involving a DI water droplet of 10 pL under ambient conditions (temperature ~ 24 ± 2 °C and relative humidity - 45%).

[0124] In an embodiment, the present invention provides that to examine the dynamic wetting behaviour (advancing and receding contact angles), the liquid is pumped / extracted at a rate of 0.1 pL / s with a maximum droplet size of 10 pL. Tilt angles are also measured with liquid droplets of 10 pL size placed on samples tilting at a speed of 4° / min. The effect of surface tension on the wetting state is examined by preparing test liquids with different surface tensions (28 to 72 mN.m’1) utilizing a water- ethanol mixture.

[0125] In an embodiment, the adhesive force of the prepared samples is determined by utilizing a force tensiometer (Biolin Scientific, Sweden) in conjunction with different liquids of varying surface tension.

[0126] In one of the embodiments, the durability of the processed nanostructured samples is evaluated under a broad spectrum of conditions concerning their wetting state and chemical and physical stability. Dewetting durability is assessed through single-droplet impingement studies performed using 15 pL droplets of different surface tension (38 to 72 mN.m1) impinging from different impact heights (10 to 100 mm) corresponding to the kinetic energies in the range of 1 to 14 kJ. The interaction between impacting liquid droplets and substrate is recorded; subsequently, the coefficient of restitution (CoR) is calculated using s = where 'h' is the maximum rebound height and 'H' is the initial height of the droplet.

[0127] Further, to assess the physical stability, samples are exposed to the simulated rain (droplet size: 1-2 mm, velocity ~7 m / sec at 1 bar pressure) for 30 min each. The amount of rain is estimated to be around 100 mm (ASTM D3779). Further dynamic stability was evaluated by immersing the samples in DI water and exposing them to vibrations of 40 ± 3 kHz at 40 °C for 10 mins in an ultrasonic bath (Labman, India). A reciprocating linear abrasion test was performed for all the samples using a universal tribometer (Rtec, USA) with a polymer (polymethyl methacrylate) as the counter surface. The operating parameters (force: 100 mN, distance: 3 mm, velocity: 2 mm / sec, acceleration: 0.1 sec) is maintained constant for 30 min, and the effect on contact angle is measured.

[0128] In one of the embodiments, the chemical stability of the samples is investigated through long-term immersion in test liquids of different pH (lemon water (pH~2), black coffee (pH~5), and buffalo milk (pH~6)). Samples is also submerged in a solution of 3.5 wt.% sodium chloride (NaCl) for 168 h with periodic assessment of the wetting behaviour. Samples are immersed in solutions with different pH values for up to 3 hrs. to check their de-wetting stability under extreme conditions. Self-cleaning experiments are carried out by spreading sand particles (average size ~ 50 pm) on SHB samples of size 10 x 10 mm2and tilting them at an inclination angle of 10° before the testing. The samples will sequentially treat with droplets of water (~3 mm diameter) dispensed slowly on the surface. The droplets' motion and interface with sand particles of different samples are compared and recorded with an optical camera, and the number of droplets necessary to obliterate the dust is calculated.

[0129] In another embodiment, the method is for the detection of adulteration of milk.

[0130] In an embodiment, the present invention provides device for detecting adulterants in milk utilizes a superhydrophobic surface.

[0131] In another embodiment, the present invention provides a device that establishes a superhydrophobic aluminium surface that is fabricated by the techniques such as hot-water treatment, abrasive machining, and friction stir processing.

[0132] In another preferred embodiment, the present invention provides device for detecting adulterants in milk utilizes a super hydrophobic aluminium surface.

[0133] In another embodiment, the present invention provides method for detecting adulterants in liquid droplet or milk by utilizing a superhydrophobic aluminium surface.

[0134] In another embodiment, the present invention provides device and method which involves Arduino programming.

[0135] In another embodiment, the device's circuit design and construction are provided wherein, the microcontroller serve as a control unit, processing signals from the sensors and executing the wetting detection algorithm. The LCD display provides a user-friendly interface, displaying the results obtained from the wetting detection process in real-time. The device operates by emitting infrared light from the IR LED onto the super hydrophobic substrate, and the photodiode detects changes in resistance caused by the liquid droplet on the substrate.

[0136] In another embodiment, the device operates on the principle of analysing the changes in the wetting characteristics / behaviours of liquid droplets, preferably of a milk on a superhydrophobic aluminium surface.

[0137] In another embodiment, the present invention provides method for quantitatively assessing and interpreting modifications in the wetting characteristics caused by adulterants in milk.

[0138] In another embodiment, the working principle of device of the present invention is as follows (figure 1(a)): • Power Supply: The 9V battery provides the necessary power to the circuit. The voltage regulator (7805) stabilizes the voltage output and ensures a constant 5V supply for the microcontroller and other components.

[0139] • Light Emission: The Infrared (IR) LED emits infrared light, which is directed towards the superhydrophobic aluminium substrate, and the liquid droplet placed between the photodiode and IR LED.

[0140] • Photodiode Detection: In the absence of a liquid droplet on the superhydrophobic substrate, the infrared light from the IR LED passes through the substrate without any significant hindrance. The photodiode, acting as a light receiver, detects the light without any substantial change in resistance.

[0141] • Wetting Detection: However, when a liquid droplet wets the superhydrophobic substrate, it alters the path of the infrared light passing through it (Figure 1(b)). The presence of the liquid droplet causes a change in the light intensity received by the photodiode, leading to a change in resistance in the photodiode circuit.

[0142] • Voltage Division: The photodiode's resistance change is converted into a voltage signal through the voltage division provided by the lOkQ resistor and the photodiode's resistance. This voltage signal is fed to the microcontroller's analogue input pin (Pin 3) through the potentiometer.

[0143] • Microcontroller Processing: The microcontroller (ATMEGA8) continuously monitors the voltage signal from the photodiode and processes it. It compares the voltage value with a predefined threshold (13) set by the potentiometer, which determines the wetting detection sensitivity.

[0144] • LCD Display: Based on the comparison result, the microcontroller determines the wetting behaviour of the liquid droplet and displays the corresponding status on the 16x2 LCD display. The LCD provides a real-time indication of the wetting characteristics of the liquid droplet on the substrate.

[0145] In an embodiment, the present invention provides that to generate the Arduino code for this device with the specified components, the Arduino IDE (Arduino Integrated Development Environment) has been used.

[0146] In another embodiment, the present invention provides a device and method which is easy to use and have real-time analytics for detection of various types of milk adulterants. In another embodiment, the present invention has application in measuring wetting detection for various scientific and industrial applications.

[0147] In another embodiment, the present invention provides a device and method which uses potentiometer that allowed users to adjust the sensitivity of the device, making it suitable for different experimental conditions and liquid-substrate combinations.

[0148] In another embodiment, the method for detection of adulterant in a milk sample comprises: operating the device by emitting infrared light from the IR LED onto the super hydrophobic substrate, and the photodiode detects changes in resistance caused by the liquid droplet on the substrate.

[0149] In another embodiment, the detection of adulterant in a milk by utilization of superhydrophobic aluminium surfaces comprising the steps of placing a milk sample on the super hydrophobic aluminium surfaces of the device, any adulterants present will alter the wetting behaviour of the droplet. The change in resistance observed by the photodiode, caused by the interaction of light with the adulterated milk droplet, will be processed by the microcontroller and displayed as a digital value on the LCD screen.

[0150] In another embodiment, the present invention provides detection of various adulterants including but not limited to Water, Maltodextrin, Ammonium sulphate, Sodium hydroxide, Sodium bicarbonate, Sodium chloride, formalin, starch, detergents, vegetable oils, synthetic chemicals, sodium salicylate, ammonium sulphate, dextrose, hydrogen peroxide, cane sugar, nitrates, sulfates, detergents, neutralizers, or combination thereof at different concentration ratios.

[0151] The wetting detection device of the present invention utilizes basic electronic components as shown in the Figure 2 (Circuit diagram) to detect changes in the wetting behaviour of liquid droplets on a substrate. The key components used in the device are as follows:

[0152] 1. Battery Source: A 9V battery acts as the power supply for the device, providing the necessary electrical energy to power the electronic components.

[0153] 2. Voltage Regulator: A 7805 voltage regulator is integrated into the circuit to stabilize the voltage output and ensure a constant 5V supply for the microcontroller (ATMEGA8) and other components. This ensures the device operates reliably and accurately, even with fluctuations in the battery voltage. 3. Microcontroller: The ATMEGA8 microcontroller is the central component of the device. It acts as the control unit, processing signals from the sensors and executing the wetting detection algorithm.

[0154] 4. LCD Display: The device features a 16x2-character LCD (LM016L) with 5x7 pixels resolution. The LCD serves as the user interface, displaying the results obtained from the wetting detection process.

[0155] 5. Sensors: The device incorporates two sensors - a Photodiode (Make: Kingbright) and an IR LED (Make: Kingbright T-l 3 / 4 (5mm) SOLID STATE LAMP) - which work together to measure changes in resistance caused by the liquid droplet on the superhydrophobic substrate.

[0156] 6. Potentiometer: The potentiometer is used to adjust the sensitivity or threshold of the device. It allows the user to control the detection range for different wetting behaviors.

[0157] 7. Resistors: Two resistors are used in the circuit. One is a lOkQ resistor, and the other is a 200Q resistor. These resistors are essential for proper voltage division and current limiting.

[0158] This device is constructed on a printed circuit board (PCB) to ensure a neat and organized arrangement of the electronic components. The microcontroller is positioned at the centre of the PCB, with the LCD display connected to one end. The photodiode and IR LED are positioned at opposite ends of the PCB. The superhydrophobic substrate, with the liquid droplet under investigation, is carefully placed between the photodiode and IR LED (Figure 2).

[0159] The circuit connections are made as follows:

[0160] • Pin 1 of the microcontroller (ATMEGA8) is connected to Ground (GND).

[0161] • Pin 2 of the microcontroller is connected to the positive terminal of the 9V battery (Bl) through a voltage regulator (U2).

[0162] • Pin 3 of the microcontroller is connected to the wiper terminal of the potentiometer, while the other two terminals of the potentiometer are connected to 5V and Ground, respectively.

[0163] • Pins 11, 12, 13, 14, 15, 16 from the microcontroller represents the digital signal pins. The Pin 23 represents an analogue signal pin along with 20, 21 Pins are connected to the BL

[0164] In an embodiment, the photodiode and IR LED are connected in a series circuit with the 200Q resistor to limit the current flowing through them. The anode of the IR LED is connected to the positive terminal of the battery, and the cathode is connected to the photodiode's anode. The photodiode's cathode is connected to the 200Q resistor, and the other end of the resistor is connected to Ground. The lOk resistor is connected between Bl and the anode of the photodiode to provide a pull-up resistor for the photodiode signal.

[0165] In another embodiment, the present invention offers a promising solution to address the challenges posed by milk adulteration. Leveraging the device's ability to detect changes in the wetting characteristic / behaviour of liquid droplets on a super hydrophobic aluminium surface, it can be adapted for the rapid and accurate detection of adulterants in milk. The device of the present invention is utilized in the context of milk adulteration detection as follows:

[0166] 1. Identification of Adulterants: The device can be configured to detect specific adulterants commonly found in milk, such as water or synthetic chemicals. When a milk sample is placed on the superhydrophobic substrate of the device, any adulterants present will alter the wetting characteristic / behaviour of the droplet. The change in resistance observed by the photodiode, caused by the interaction of light with the adulterated milk droplet, will be processed by the microcontroller and displayed as a digital value on the LCD screen.

[0167] 2. Real-time Results: One of the key advantages of this innovation is its real-time capability, enabling quick analysis and immediate results. As the device operates with simple electronics and requires minimal user training, it can be deployed at various levels of the milk supply chain, from dairy farms to retail outlets, to ensure on-the-spot adulteration screening.

[0168] 3. Cost-effective and User-friendly: The simplicity of the device's design and the use of basic electronic components make it a cost-effective solution, accessible even in resource- constrained settings. Its user-friendly interface and minimal maintenance requirements make it feasible for widespread implementation, including in rural areas.

[0169] 4. Enhancing Regulatory Compliance: By facilitating rapid and reliable adulteration detection, the wetting detection device can contribute to enhancing regulatory compliance and enforcement efforts in the dairy industry. Regular monitoring and screening of milk samples can deter adulteration practices and promote accountability among dairy producers and suppliers.

[0170] EXAMPLES: The objective is to assess the device's efficacy in identifying the presence and concentration of these adulterants, contributing to the development of a practical and efficient tool for milk adulteration detection.

[0171] Fresh buffalo milk samples were collected from various sources and divided into multiple sets for testing. Adulterant substances, including Water, Maltodextrin, Ammonium sulphate, Sodium hydroxide, Sodium bicarbonate, and Sodium chloride, were added to the milk samples at concentrations of 0.5, 1.0, 1.5, and 2.0 grams per litre (g / L) (these are the ratios used for adulteration mixture). The device was employed for the analysis. The device utilizes simple electronic components and innovative sensing techniques to measure alterations in the wetting characteristics / behaviours of liquid droplets on a superhydrophobic aluminium surface. The device was calibrated using pure buffalo milk as a control to establish a baseline for wetting behaviour. Subsequently, adulterated milk samples were analysed using the device, recording the change in resistance observed by the photodiode. The resulting digital values were displayed on the connected LCD screen.

[0172] Example-1: i) Effect of Maltodextrin Adulteration

[0173] The observed contact angle values for pure buffalo milk and its mixtures with Maltodextrin on the superhydrophobic aluminium substrate as shown in Figure 3. This can be explained by the interplay of surface tension, intermolecular forces, and molecular interactions at the liquid-substrate interface. Pure buffalo milk, when placed on the superhydrophobic substrate, forms a nearly spherical droplet with a high contact angle of 9S~ 156°. This is because buffalo milk contains a complex mixture of proteins, fats, carbohydrates, and other components. The intermolecular forces within the milk droplet and the interactions between milk molecules and the substrate play a crucial role in determining the contact angle. The high contact angle indicates that the liquid droplet has minimal interaction with the superhydrophobic aluminium surface, and the droplet retains a nearly spherical shape due to the surface tension dominance over the solid-liquid interactions.

[0174] As Maltodextrin is added as an adulterant to the pure buffalo milk at different concentrations (0.5, 1.0, 1.5, and 2.0 g / L), its presence influences the molecular interactions at the liquid-substrate interface (Figure 3(a)). At 0.5 g / L of Maltodextrin, the adulterant molecules begin to interact with the milk molecules at the interface. However, the concentration of Maltodextrin is relatively low, and its effect on changing the wetting behaviour of the droplet is not as significant. As a result, the contact angle increases to 0s~ 148° but remains lower than the pure buffalo milk's contact angle. At 2.0 g / L of Maltodextrin, with a higher concentration of Maltodextrin, the adulterant molecules form a more substantial network at the liquid-substrate interface, competing with the milk molecules' interactions. The Maltodextrin molecules hinder the spreading of the droplet on the superhydrophobic substrate, leading to a further increase in the contact angle to 9S~ 152°. The increase in the contact angle values with the addition of Maltodextrin can be attributed to the changes in the liquid's wetting behaviour on the superhydrophobic aluminium surface.

[0175] As the concentration of Maltodextrin increases, its molecules increasingly dominate the interactions at the liquid-substrate interface, causing the droplet to be less likely to spread out on the substrate. Consequently, the contact angle increases, indicating reduced wetting of the droplet on the superhydrophobic aluminium surface. The observed increase in digital values on the device (Figure 3(c)) and the corresponding increase in surface tension values (Figure 3(b)) with the addition of Maltodextrin as an adulterant to pure buffalo milk samples can be explained by the changes in wetting behaviour and surface interactions on the superhydrophobic substrate.

[0176] Pure buffalo milk has a surface tension of G ~ 58 mN / m when placed on the superhydrophobic aluminium substrate. The high surface tension is a characteristic property of pure milk, which tends to form a nearly spherical droplet with minimal spreading on the substrate due to the cohesive forces between its molecules. When Maltodextrin is added to pure buffalo milk at a concentration of 0.5 g / L, the surface tension increases to 68.1 mN / m. This increase in surface tension indicates that the presence of Maltodextrin disrupts the cohesive forces of the milk molecules at the liquid-substrate interface. As a result, the droplet of adulterated milk tends to spread out more on the substrate, leading to a higher surface tension value. At a higher concentration of Maltodextrin (2.0 g / L), the surface tension further increases to 71 mN / m. The higher surface tension indicates that the adulterant molecules have a more significant effect on disrupting the cohesive forces of the milk, causing the droplet to spread out even more on the superhydrophobic aluminium surface.

[0177] When pure buffalo milk is placed on the superhydrophobic substrate (Figure 4), the wetting detection device records a digital value of 47. This value represents the electrical response of the photodiode to the wetting behaviour of the milk droplet on the substrate. At this stage, the milk droplet forms a nearly spherical shape with minimal interaction with the substrate, resulting in a specific electrical response. As Maltodextrin is added to the pure buffalo milk at a concentration of 0.5 g / L, the adulterant molecules interact with the milk molecules at the liquid-substrate interface. The presence of Maltodextrin affects the wetting behaviour of the droplet, causing it to spread out less on the superhydrophobic substrate. This reduced wetting results in a change in the electrical response of the photodiode, leading to a lower digital value of 39 compared to pure buffalo milk.

[0178] At a higher concentration of Maltodextrin (2.0 g / L), the adulterant molecules form a denser network at the liquid-substrate interface, further inhibiting the spreading of the droplet on the superhydrophobic aluminium surface. This significant reduction in wetting behaviour results in a higher contact angle and a corresponding change in the electrical response of the photodiode, leading to a higher digital value of 43 compared to pure buffalo milk. The gradual increase in digital values with the increase in Maltodextrin concentration indicates the device's sensitivity to detect changes in the wetting behaviour caused by adulteration. Higher digital values are indicative of reduced wetting and increased contact angles due to the presence of Maltodextrin.

[0179] Example-2: ii) Effect of Ammonium sulphate Adulteration

[0180] In Figure 5 (a)), with a higher concentration of Ammonium sulphate (2.0 g / L), the adulterant molecules form a denser network at the liquid-substrate interface, further inhibiting the spreading of the droplet on the superhydrophobic substrate. This significant reduction in wetting behaviour results in a higher contact angle and a corresponding change in the contact angle value, leading to the highest value of 0s~ 148° observed for 2.0 g / L of Ammonium sulphate.

[0181] The gradual increase in contact angle values with the increase in Ammonium sulphate concentration indicates the device's sensitivity to detect changes in the wetting behaviour caused by adulteration. Higher contact angle values are indicative of reduced wetting and increased droplet roundness due to the presence of Ammonium sulphate. The observed increase in digital values on the device (Figure 5 (c)) and the corresponding increase in surface tension values (Figure 5 (b)) with the addition of Ammonium sulphate as an adulterant to pure buffalo milk samples on the superhydrophobic substrate can be explained by the changes in wetting behaviour and surface interactions on the superhydrophobic substrate. As Ammonium sulphate is added to the pure buffalo milk at a concentration of 0.5 g / L, the adulterant molecules interact with the milk molecules at the liquidsubstrate interface. When Ammonium sulphate is added to pure buffalo milk at a concentration of 0.5 g / L, the surface tension increases to G ~ 63.2 mN / m. This increase in surface tension indicates that the presence of Ammonium sulphate disrupts the cohesive forces of the milk molecules at the liquid-substrate interface. As a result, the droplet of adulterated milk tends to spread out more on the substrate, leading to a higher surface tension value. At a higher concentration of Ammonium sulphate (2.0 g / L), the surface tension further increases to c ~ 65 mN / m. The higher surface tension indicates that the adulterant molecules have a more significant effect on disrupting the cohesive forces of the milk, causing the droplet to spread out even more on the superhydrophobic substrate.

[0182] The presence of Ammonium sulphate affects the wetting behaviour of the droplet, causing it to spread out less on the superhydrophobic substrate. This reduced wetting results in a change in the electrical response of the photodiode, leading to a lower digital value of 36 compared to pure buffalo milk (Figure 6). At a higher concentration of Ammonium sulphate (2.0 g / L), the adulterant molecules form a denser network at the liquid-substrate interface, further inhibiting the spreading of the droplet on the superhydrophobic substrate. This significant reduction in wetting behaviour results in a higher contact angle and a corresponding change in the electrical response of the photodiode, leading to a higher digital value of 39 compared to pure buffalo milk. The gradual increase in digital values with the increase in Ammonium sulphate concentration indicates the device's sensitivity to detect changes in the wetting behaviour caused by adulteration. Higher digital values are indicative of reduced wetting and increased contact angles due to the presence of Ammonium sulphate.

[0183] Example-3: iii) Effect of Sodium hydroxide Adulteration

[0184] When Sodium hydroxide is added to the pure buffalo milk at a concentration of 0.5 g / L (Figure 7 (a)), the adulterant molecules interact with the milk molecules at the liquid-substrate interface. The presence of Sodium hydroxide affects the wetting behaviour of the droplet, causing it to spread out more on the superhydrophobic substrate. This increased wetting results in a change in the contact angle, leading to a lower value of 9S~ 133° compared to pure buffalo milk. With a higher concentration of Sodium hydroxide (2.0 g / L), the adulterant molecules form a more substantial network at the liquid-substrate interface, further promoting the spreading of the droplet on the superhydrophobic substrate. This significant increase in wetting behaviour results in a lower contact angle and a corresponding change in the contact angle value, leading to the lowest value of 9S~ 137° observed for 2.0 g / L of Sodium hydroxide. When Sodium hydroxide is added to pure buffalo milk at a concentration of 0.5 g / L, the surface tension increases to c ~ 53.3 mN / m (Figure 7(b)). The similar trend also observed as in case with the digital values on the device (Figure 7(c)). This increase in surface tension indicates that the presence of Sodium hydroxide disrupts the cohesive forces of the milk molecules at the liquid-substrate interface. As a result, the droplet of adulterated milk tends to spread out more on the substrate, leading to a higher surface tension value. At a higher concentration of Sodium hydroxide (2.0 g / L), the surface tension further increases to c ~ 55.3 mN / m. The higher surface tension indicates that the adulterant molecules have a more significant effect on disrupting the cohesive forces of the milk, causing the droplet to spread out even more on the superhydrophobic substrate.

[0185] The increase in digital values on the device and the corresponding increase in surface tension values with the addition of Sodium hydroxide as an adulterant to pure buffalo milk samples can be attributed to the changes in the wetting behaviour of the liquid droplet caused by the presence of Sodium hydroxide. When pure buffalo milk is placed on the superhydrophobic substrate, the wetting detection device records a digital value of 47 (Figure 8). This value represents the electrical response of the photodiode to the wetting behaviour of the milk droplet on the substrate. At this stage, the milk droplet forms a nearly spherical shape with minimal interaction with the substrate, resulting in a specific electrical response. As Sodium hydroxide is added to the pure buffalo milk at a concentration of 0.5 g / L, the adulterant molecules interact with the milk molecules at the liquid-substrate interface. The presence of Sodium hydroxide affects the wetting behaviour of the droplet, causing it to spread out less on the superhydrophobic substrate. This reduced wetting results in a change in the electrical response of the photodiode, leading to a lower digital value of 23 compared to pure buffalo milk. At a higher concentration of Sodium hydroxide (2.0 g / L), the adulterant molecules form a denser network at the liquid-substrate interface, further inhibiting the spreading of the droplet on the superhydrophobic substrate. This significant reduction in wetting behaviour results in a higher contact angle and a corresponding change in the electrical response of the photodiode, leading to a higher digital value of 28 compared to pure buffalo milk.

[0186] Example-4: iv) Effect of Sodium bicarbonate Adulteration

[0187] As Sodium bicarbonate is added to pure buffalo milk at a concentration of 0.5 g / L, the adulterant molecules interact with the milk molecules at the liquid-substrate interface. Sodium bicarbonate is a soluble salt, and its presence affects the wetting behaviour of the droplet. The interaction between Sodium bicarbonate and the milk components at the droplet-substrate interface reduces the cohesive forces between milk molecules and allows the droplet to spread out more on the superhydrophobic substrate. This increased spreading leads to a change in the contact angle, resulting in a lower value of 0s~ 140° compared to pure buffalo milk (Figure 9-(a)). At a higher concentration of Sodium bicarbonate (2.0 g / L), the interactions between the adulterant and milk components become more pronounced at the liquid-substrate interface. This stronger interaction promotes even more spreading of the droplet on the superhydrophobic substrate, further reducing the contact angle. As a result, the contact angle decreases, and the lowest value 0s~ 144° is observed for 2.0 g / L of Sodium bicarbonate. The gradual increase in contact angle values with the increase in Sodium bicarbonate concentration indicates the device's sensitivity to detect changes in the wetting behaviour caused by adulteration. Lower contact angle values are indicative of increased wetting and reduced contact angles due to the presence of Sodium bicarbonate. As depicted in the Figure 9(c), the digital values displayed on the wetting detection device also increase with the rise in the concentration of the adulterant Sodium bicarbonate in the quantities of 0.5, 1.0, 1.5, and 2.0 grams per Litre (g / L) when mixed with pure buffalo milk samples on the superhydrophobic substrate. The highest digital value of 36 is observed for 2.0 g / L, while a digital value of 30 is observed for 0.5 g / L.

[0188] When Sodium bicarbonate is added to pure buffalo milk at a concentration of 0.5 g / L, the surface tension increases to c ~ 55.4 mN / m (Figure 9(b)). This increase in surface tension indicates that the presence of Sodium bicarbonate disrupts the cohesive forces of the milk molecules at the liquidsubstrate interface.

[0189] As a result, the droplet of adulterated milk tends to spread out more on the substrate, leading to a higher surface tension value. At a higher concentration of Sodium bicarbonate (2.0 g / L), the surface tension further increases to c ~ 56.8 mN / m. The higher surface tension indicates that the adulterant molecules have a more significant effect on disrupting the cohesive forces of the milk, causing the droplet to spread out even more on the superhydrophobic substrate.

[0190] In contrast, the digital value for pure buffalo milk is 47 (Figure 10). As Sodium bicarbonate is added to pure buffalo milk at a concentration of 0.5 g / L, the adulterant molecules interact with the milk molecules at the liquid-substrate interface. Sodium bicarbonate is a soluble salt, and its presence affects the wetting behaviour of the droplet. The interactions between Sodium bicarbonate and the milk components at the droplet-substrate interface reduce the cohesive forces between milk molecules and promote more spreading of the droplet on the superhydrophobic substrate. This increased wetting results in a change in the electrical response of the photodiode, leading to a lower digital value of 30 compared to pure buffalo milk. At a higher concentration of Sodium bicarbonate (2.0 g / L), the interactions between the adulterant and milk components become more pronounced at the liquid-substrate interface. This further reduces the cohesive forces within the milk droplet, causing it to spread out even more on the superhydrophobic substrate. As a result, the electrical response of the photodiode changes, and the digital value increases to 36 for 2.0 g / L of Sodium bicarbonate. The gradual increase in digital values with the increase in Sodium bicarbonate concentration indicates the device's sensitivity to detect changes in the wetting behaviour caused by adulteration. Higher digital values are indicative of increased wetting and reduced droplet cohesion due to the presence of Sodium bicarbonate.

[0191] Example-5: v) Effect of Sodium chloride Adulteration

[0192] As Sodium chloride is added to pure buffalo milk at a concentration of 0.5 g / L, the adulterant molecules interact with the milk molecules at the liquid-substrate interface. Sodium chloride is a soluble salt, and its presence affects the wetting behaviour of the droplet. The interactions between Sodium chloride and the milk components at the droplet-substrate interface reduce the cohesive forces between milk molecules and promote more spreading of the droplet on the superhydrophobic substrate. This increased wetting results in a change in the contact angle, leading to a lower value of 0s~ 151° compared to pure buffalo milk (Figure 11(a)). At a higher concentration of Sodium chloride (2.0 g / L), the interactions between the adulterant and milk components become more pronounced at the liquid-substrate interface. This further reduces the cohesive forces within the milk droplet, causing it to spread out even more on the superhydrophobic substrate. As a result, the contact angle decreases, and the highest value of 0s~ 153° is observed for 2.0 g / L of Sodium chloride. The gradual increase in contact angle values with the increase in Sodium chloride concentration indicates the device's sensitivity to detect changes in the wetting behavior caused by adulteration. Lower contact angle values are indicative of increased wetting and reduced droplet cohesion due to the presence of Sodium chloride.

[0193] As Sodium chloride is added to pure buffalo milk at a concentration of 0.5 g / L, the adulterant molecules interact with the milk molecules at the liquid-substrate interface. Sodium chloride is a soluble salt, and its presence affects the wetting behaviour of the droplet. The interactions between Sodium chloride and the milk components at the droplet-substrate interface reduce the cohesive forces between milk molecules and promote more spreading of the droplet on the superhydrophobic substrate. This increased wetting results in a change in the electrical response of the photodiode, leading to a lower digital value of 42 compared to pure buffalo milk (Figure 11(c)). At a higher concentration of Sodium chloride (2.0 g / L), the interactions between the adulterant and milk components become more pronounced at the liquid-substrate interface. This further reduces the cohesive forces within the milk droplet, causing it to spread out even more on the superhydrophobic substrate. As a result, the electrical response of the photodiode changes, and the digital value increases to 43 for 2.0 g / L of Sodium chloride (Figure 12).

[0194] Pure buffalo milk has a surface tension of c ~ 58 mN / m when placed on the superhydrophobic substrate. The high surface tension is a characteristic property of pure milk, which tends to form a nearly spherical droplet with minimal spreading on the substrate due to the cohesive forces between its molecules. When Sodium chloride is added to pure buffalo milk at a concentration of 0.5 g / L, the surface tension increases to c ~ 72.8 mN / m (Figure 11(b)). This increase in surface tension indicates that the presence of Sodium chloride disrupts the cohesive forces of the milk molecules at the liquidsubstrate interface. As a result, the droplet of adulterated milk tends to spread out more on the substrate, leading to a higher surface tension value. At a higher concentration of Sodium chloride (2.0 g / L), the surface tension further increases to c ~ 74 mN / m. The higher surface tension indicates that the adulterant molecules have a more significant effect on disrupting the cohesive forces of the milk, causing the droplet to spread out even more on the superhydrophobic substrate.

[0195] Example-6: vi) Effect of Water Adulteration

[0196] As Water is added to pure buffalo milk at a concentration of 0.5 g / L, the interactions between water molecules and milk components at the liquid-substrate interface start to reduce the cohesive forces within the milk droplet. This leads to a slight increase in the wetting of the droplet on the superhydrophobic substrate, causing the contact angle to increase to 0s~ 157° (Figure 13(a)). At this concentration, the effect of water on the droplet's wetting behaviour is relatively small, and the contact angle remains like that of pure buffalo milk. As the concentration of Water is increased to 2.0 g / L, the interactions between the adulterant and milk components become more pronounced at the liquid-substrate interface. The cohesive forces within the milk droplet further reduce due to the presence of a higher concentration of Water. As a result, the droplet tends to spread out more on the superhydrophobic substrate, leading to an increase in the contact angle to 0s~ 161°. The higher contact angle value indicates that the droplet's wetting behavior has been significantly affected by the presence of Water. The gradual increase in contact angle values with the increase in Water concentration indicates the device's sensitivity to detect changes in the wetting behaviour caused by adulteration. Higher contact angle values are indicative of increased wetting and reduced droplet cohesion due to the presence of Water.

[0197] When Water is added to pure buffalo milk at a concentration of 0.5 g / L, the surface tension increases to G ~ 62.4 mN / m (Figure 13(b)). This increase in surface tension indicates that the presence of Water disrupts the cohesive forces of the milk molecules at the liquid-substrate interface. As a result, the droplet of adulterated milk tends to spread out more on the substrate, leading to a higher surface tension value. At a higher concentration of Water (2.0 g / L), the surface tension further increases to c ~ 66 mN / m. The higher surface tension indicates that the adulterant molecules have a more significant effect on disrupting the cohesive forces of the milk, causing the droplet to spread out even more on the superhydrophobic substrate.

[0198] As Water is added to pure buffalo milk at a concentration of 0.5 g / L, the interactions between water molecules and milk components at the liquid-substrate interface start to reduce the cohesive forces within the milk droplet. This leads to a slight increase in the wetting of the droplet on the superhydrophobic substrate, causing the digital value to increase to 48 (Figure 13(c)).

[0199] At this concentration, the effect of Water on the droplet's wetting behaviour is relatively small, and the digital value remains similar to that of pure buffalo milk. As the concentration of Water is increased to 2.0 g / L, the interactions between the adulterant and milk components become more pronounced at the liquid-substrate interface. The cohesive forces within the milk droplet further reduce due to the presence of a higher concentration of Water. As a result, the droplet tends to spread out more on the superhydrophobic substrate, leading to an increase in the digital value to 51. The higher digital value indicates that the droplet's wetting behaviour has been significantly affected by the presence of Water. The gradual increase in digital values with the increase in Water concentration indicates the device's sensitivity to detect changes in the wetting behaviour caused by adulteration. Higher digital values are indicative of increased wetting and reduced droplet cohesion due to the presence of Water (Figure 14).

[0200] Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses of the invention and obvious modifications and equivalents thereof. Thus, from the foregoing description, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein.

[0201] Accordingly, it is not intended that the scope of the foregoing description be limited to the description set forth above, but rather that such description be construed as encompassing all of the features of patentable novelty that reside in the present invention, including all the features and embodiments that would be treated as equivalents thereof by those skilled in the relevant art. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above but should be determined only by a fair reading of complete specification to follow.

[0202] It is to be understood that the present invention is susceptible to modifications, changes and adaptations by those skilled in the art. Such modifications, changes, adaptations are intended to be within the scope of the present invention. The above and other features of the present invention will be more clearly described in the complete specification which will be filed pursuant to the present provisional specification.

Claims

WE CLAIM:

1. A superhydrophobic surfaces for the detection of an unauthorized substances / adulterants of a liquid-droplet, characterized in that, the superhydrophobic surfaces are established on an aluminium alloy -based substrate having a chemical composition comprising: i) 4.0-6.5 wt % Mg, ii) 0.3 wt % Si, iii) 0.1-0.5 wt % Fe, iv) 0.5-0.9 wt % Mn, v) 0.23 wt % Zn, vi) 0.2 wt % Cu, vii) 0.14 wt % Ti, viii) 0.04-0.26 wt % Cr and ix) the balance was Al.

2. The superhydrophobic surfaces as claimed in claim 1, wherein, the substrate is fabricated by friction stir processing (FSP), stationery friction processing (SFP), hot-water treatment, and abrasive machining.

3. The superhydrophobic surfaces as claimed in claim 1, wherein, the unauthorized substances / adulterants are detected by measuring the alteration in the wetting characteristics / behaviour of an adulterants.

4. The superhydrophobic surfaces as claimed in claim 1 , wherein, the superhydrophobic surfaces is a superhydrophobic aluminum surface.

5. The superhydrophobic surfaces as claimed in claim 1, wherein, the liquid droplet is milk or milk adulterants, honey, soy milk, almond milk, coconut milk, mustard oil, palm oil, sunflower oil, soyabean oil, olive oil, coconut oil, groundnut oil, sesame oil, rice bran oil, or combination thereof.

6. The superhydrophobic surface as claimed in claim 1, wherein, unauthorized substances / adulterants are selected from the group comprising of water, maltodextrin,urea / ammonium sulphate, caustic soda / sodium hydroxide, sodium bicarbonate, sodium chloride, formalin, starch, detergents, vegetable oils, synthetic chemicals, sodium salicylate, ammonium sulphate, dextrose, hydrogen peroxide, cane sugar, nitrates, sulfates, detergents, neutralizers, or combination thereof.

7. The superhydrophobic surfaces as claimed in claim 1, wherein, the wetting characteristics / behavior of an adulterants are measured by change in contact angle across a superhydrophobic surfaces caused by the presence of unauthorized substances / adulterants in liquid-droplet.

8. The superhydrophobic surfaces as claimed in claim 7, wherein, the change in contact angle is attributed by change in the electrical resistance across the superhydrophobic surfaces.

9. A device for the detection of an unauthorized substances / adulterants in a liquid-droplet, comprises: a) a substate; and b) integrated electronic components, wherein, the substrate is fabricated by the superhydrophobic aluminum surface and the device detects the unauthorized substances / adulterants by measuring the wetting characteristics / behavior of adulterants measured by the change in contact angle across the superhydrophobic surfaces.

10. The device as claimed in claim 9, wherein, the change in contact angle across the superhydrophobic surfaces is caused by the presence of unauthorized substances / adulterants in liquid-droplet by an innovative sensing technique based on the detection of changes in resistance caused by the liquid droplet on the superhydrophobic surfaces.

11. The device as claimed in claim 9, wherein the integrated electronic components comprise: i) a microcontroller, ii) LCD display, and iii) an integrated sensor.

12. The device as claimed in claim 9, wherein the integrated sensor comprises a photodiode sensor, and an IR LED sensor.

13. The device as claimed in claim 9, wherein the microcontroller serves as a control unit, processing signals from the sensors and executing the wetting detection algorithm.

14. The device as claimed in claim 9, wherein the LCD display provides a user-friendly interface, displaying the results obtained from the wetting detection process in real-time.

15. The device as claimed in claim 9, wherein the photodiode sensor, acts as a light receiver, detects the light without any substantial change in resistance.

16. The device as claimed in claim 9, wherein the IR LED sensor emits infrared light, which is directed towards the superhydrophobic aluminum surface, and the liquid droplet placed between the photodiode sensor and IR LED sensor.

17. The device as claimed in claim 9, wherein the device operates by emitting infrared light from the IR LED sensor onto the superhydrophobic substrate, and the photodiode detects changes in resistance caused by the liquid droplet on the superhydrophobic aluminum surfaces.

18. The device as claimed in claim 9, wherein, the device works on Arduino programming.

19. The device as claimed in claim 9, further comprises a battery source, a voltage regulator, a potentiometer and resistors.

20. The device as claimed in claim 9, wherein, the device is constructed on a printed circuit board (PCB).

21. The device as claimed in claim 9, wherein, the device is for the detection of the adulterant of the following milk, honey, soy milk, almond milk, coconut milk, mustard oil, palm oil, sunflower oil, soyabean oil, olive oil, coconut oil, groundnut oil, sesame oil, rice bran oil, or combination thereof22. A device for the detection of milk adulterants, comprises: a) a superhydrophobic aluminum surfaces; and b) integrated electronic components,wherein, the device detects the unauthorized substances / adulterants by measuring the wetting characteristics / behavior of adulterants measured by change in contact angle across a superhydrophobic surfaces caused by the presence of unauthorized substances / adulterants in liquid-droplet, with innovative sensing technique based on the detection of changes in resistance caused by the liquid droplet on the superhydrophobic surfaces.

23. A method for the detection of an unauthorized substances / adulterants of a liquid-droplet, the method comprises: a) identification of adulterants by placing liquid droplet on the superhydrophobic surfaces, b) the change in resistance observed by the photodiode, caused by the interaction of light with the adulterated liquid-droplet, will be processed by the microcontroller and displayed as a digital value on the LCD screen. wherein, the unauthorized substances / adulterants are detected by measuring the wetting characteristics / behavior of an adulterants.

24. The method as claimed in claim 23, wherein, the method is for the detection of adulteration of milk.

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