Browsing by Author "Kala, Prateek"

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1 3D-printed smart functional prototypes as sensors and actuators for robotic applications
(De Gruyter, 2024) Kala, Prateek
Soft robotics, inspired by nature, is a trending research area that is based on material science and the available mechanism (pneumatic, thermal, magnetic, electrostatic, etc.) to activate them. In the recent past, polylactic acid (PLA) has shown promising material characteristics, and researchers explored the 4D printing of PLA-based functional prototypes that can be used for high-strength biomedical applications for bovines. But hitherto, little has been explored about the sensing and actuation capabilities of PLA for implantable robotic applications in bovine. In this study, PLA extracted from biomedical waste has been used to prepare the functional prototypes (implants in bovine). Further, it has been primarily recycled by varying number of shredding cycles, and finally, feedstock filaments of the same have been prepared on the single screw extruder. For analyzing the sensing and actuation capabilities of the recycled material, the prototypes were fabricated on the fused deposition modeling setup using the following process parameters: raster angle, 45°; infill pattern, grid; printing speed, 40 mm/s; and infill density, 50%. Initially, the pressure-based sensor was designed in the high-frequency structure simulator simulation software and then tested on the vector network analyzer setup to observe the dielectric properties, that is, dielectric constant (ϵr) and loss tangent (tan δ) under the effect of pressure. Further, a hydrothermal actuator for robotic application has been programmed by mechanical force, and the shape recovery of the deformed prototype has been observed under the effect of hydrothermal stimuli. The change in dielectric properties (ϵr and tan δ) of the recycled material has been observed through the insertion loss (S21) versus resonant frequency (fr), which may be used for online health monitoring of patients through a Bluetooth device by observing the electromagnetic signal in the industrial, scientific, and medical (ISM) band.
3D printed hernia mesh implant: a conformability study
(Open Exploration Publishing., 2024-09) Kala, Prateek
This study aims to explore the sensing capabilities of polyvinylidene fluoride-hydroxyapatite-chitosan (PVDF-HAP-CS) composite-based hernia mesh implants (of conformal/planar design), followed by in-vitro analysis for better understanding of the bio-stability in the patient’s body. Methods: For analyzing the sensing capabilities, a microstrip patch antenna (MPA)-based implantable sensor [with 17-4 precipitate hardened (PH) stainless steel (SS) (bio-compatible) and Cu alloy (non-biocompatible) materials as conducting plane/patch with PVDF-HAP-CS as dielectric material] has been considered separately in this study. Primarily, in this study, the 3D models of the hernia mesh implant have been designed in the high-frequency structure simulator (HFSS) software, and the sensing behaviour of the same has been recorded.
3D-printed conformal sensors for health monitoring of bovine post diaphragmatic hernia surgery: a review
(Emerald, 2024-04) Kala, Prateek
Some studies have been reported in the past on diaphragmatic hernia (DH) surgery techniques using additive manufacturing (AM) technologies, symptoms of a hernia and post-surgery complications. But hitherto little has been reported on bibliographic analysis (BA) for health monitoring of bovine post-DH surgery for long-term management. Based on BA, this study aims to explore the sensor fabrication integrated with innovative AM technologies for health monitoring assistance of bovines post-DH surgery.
Analysis of a hybrid ultrasonic horn profile using finite element analysis
(Elsevier, 2021) Kala, Prateek
Ultrasonic machining is among the non-conventional machining technique which is used to machine very hard and brittle material with help of abrasives. The ultrasonic horn is the most important part of USM which amplifies the vibration available at the transducer end to attain a required amplification factor. In the present research paper, an attempt has been made to develop a new variant of ultrasonic horn which could result in maximum magnification factor with minimum induced stresses. A comparative analysis has been made among eight different horn shapes using Modal & Harmonic Analysis in commercially available finite element package i.e. ANSYS and a new design profile i.e. a hybrid horn has been presented to attain maximum amplification factor with a reduction in the equivalent stresses.
Analysis of Surface Finish Improvement during Ultrasonic Assisted Magnetic Abrasive Finishing on Chemically treated Tungsten Substrate
(Elsevier, 2017) Kala, Prateek
In the era of globalization, the demand of new products with advanced material and process technologies is increasing. Conventional manufacturing techniques are not capable to process the advanced engineering materials with stringent properties. This paper presents a novel approach to finish some advanced engineering materials with stringent properties, which is a challenge for existing conventional machining processes. In this study the positive outcomes of Magnetic Abrasive Finishing (MAF), Chemical-Mechanical Polishing (CMP), and ultrasonic vibrations have been integrated and a novel finishing process Chemo Ultrasonic Assisted Magnetic Abrasive Finishing (CUMAF) has been developed. The machining performance has been enhanced with the process resulting in better surface finish and reduced finishing time. In order to establish the process, an experimental study was done to analyze the influence of five different process variables on surface roughness of workpiece. The response surface methodology and analysis of variance was used to design the experiments and analyze the results respectively. A regression model was also developed and validated, to foresee the process response. Optimization of the model was carried out at the end to obtain the best performance.
Bibliometric Analysis-Based Review of Fused Deposition Modeling 3D Printing Method (1994–2020)
(Mary Ann Liebert, 2021-08) Kala, Prateek
This study aimed at the detailed bibliometric analysis (BA) of fused deposition modeling (FDM) to understand the trend and research area. Web of Science database was used for extracting data using keywords, and 2793 documents were analyzed. From the analysis, the most influential and productive authors, countries, sources, and so on were identified and corresponding interrelations were represented by a three-field plot. Lotka's law was derived for author productivity and its reliability was verified by the Kolmogorov–Smirnov (K–S) test. Bradford's law was used for identifying the core sources contributing to the field of FDM. From the trend topic analysis, it was found that initially the research was focused upon removing error related to deposition as well as part orientation, but with the course of time, it diversified to include topics such as optimization of printing parameters, materials, and applications. Based on the inferences from BA, the article also discusses on current research trend and highlights certain future areas for research work.
Chemo Assisted Magnetic Abrasive Finishing: Experimental Investigations
(Elsevier, 2015) Kala, Prateek
In modern industries with advancement of technology advanced engineering materials are needed to be used like Tungsten, Titanium alloys, ceramics, various composites etc. These materials possess some special characteristics such as high hardness, high wear resistance, high toughness, high strength etc. which make them preferred over conventional materials in modern industries. Due to the stringent properties these materials are difficult to process. Different conventional finishing processes like grinding, lapping, honing, buffing etc. are generally inefficient in finishing these materials. Although processes like abrasive flow machining, magnetic field assisted finishing processes and chemo-mechanical finishing may be used but these may be less productive. Therefore a new process which uses combination of chemical oxidation and magnetic field assisted abrasion (magnetic abrasive finishing) has been conceived in the present work for faster processing.
Comparison of finishing characteristics of two paramagnetic materials using double disc magnetic abrasive finishing
(Elsevier, 2015-01) Kala, Prateek
Present paper demonstrates the application of double disc magnetic abrasive finishing (DDMAF) process, on planar paramagnetic workpieces (copper alloy and stainless steel) of different mechanical properties like flow stress, hardness, shear modulus, etc. The copper alloy and stainless steel work pieces have been finished using DDMAF process. The experiments were performed based on a response surface methodology. The results obtained after finishing have been analyzed to determine the effect of different process parameters like working gap, rotational speed, percentage weight of abrasive, abrasive mesh size and feed rate for individual work material and to study various interaction effects that may significantly affect the finishing performance of the process. The outcomes of the analysis so obtained for the two different work materials have been critically compared to understand the effect of the considered process parameters based on mechanical properties. The scanning electron microscopy was also conducted on the work piece surface to understand the possible mechanism of material removal and the surface morphology produced.
Development of a deposition framework for implementation of a region-based adaptive slicing strategy in arc-based metal additive manufacturing
(Emerald, 2022-03) Kala, Prateek
This study aims to develop and demonstrate a deposition framework for the implementation of a region-based adaptive slicing strategy for the Tungsten Inert Gas (TIG) welding-based additive manufacturing system. The present study demonstrates a deposition framework for implementing a novel region-based adaptive slicing strategy termed as Fast Interior and Accurate Exterior with Constant Layer Height (FIAECLH).
Effect of Arc Polarity on the Quality of Deposition in GTAW Welding-Based Additive Manufacturing Process: A Preliminary Study
(World Scientific, 2022) Kala, Prateek
A Gas tungsten arc welding (GTAW)-based additive manufacturing has a potential for manufacturing metallic parts with better dimensional accuracy and dense structure. This paper discusses the issues in the GTAW-based metal deposition process for the positive and negative polarity of the welding electrode in the direct current circuit. The effect of direct current electrode positive (DCEP) and direct current electrode negative (DCEN) polarity on GTAW-based metal deposition process has been discussed. The experimental study has been done with a constant voltage source of ESAB Caddy 2200i welding machine and the metal beads were deposited on the substrate plate of mild steel. The results of these experiments showed that the metal deposited using DCEN polarity has a better dimensional accuracy over DCEP polarity due to its stability in arc formation and proper transmission of heat. The experimental investigation showed that the DCEP polarity causes the deterioration of the tungsten electrode after a few trials. The work done in this paper will help to distinguish between the use of DCEP polarity and DCEN polarity in GTAW-based additive manufacturing process for depositing the metal with better dimensional accuracy and better surface finish.
Effect of deposition orientations on dimensional and mechanical properties of the thin-walled structure fabricated by tungsten inert gas (TIG) welding-based additive manufacturing process
(Springer, 2020-02) Murali, Palla; Kala, Prateek
Welding-based additive manufacturing can potentially produce a cost-effective process for the production of dense metallic parts. Tungsten inert gas (TIG) welding-based additive manufacturing process uses wire as a filler material and offers a high deposition rate with low spattering. In this study, different orientations of wire feeding nozzle and TIG welding torch, such as front wire feeding (FWF), back wire feeding (BWF), and side wire feeding (SWF), were investigated for thin-walled metal deposition with enhanced dimensional accuracy and mechanical properties. The dimensional accuracy of thin-walls deposited at four different orientations were investigated in terms of deposition height and deposition width. The FWF orientation with higher wire feeding angle and SWF orientation produced poor dimensional accuracy in the deposition. FWF orientation with normal wire feeding angle and BWF orientation provided a decent dimensional accuracy and surface appearance. The deposited samples exhibited a similar trend for Vickers microhardness, residual stress, and microstructure for the four different wire feeding orientations.
Experimental investigation into depositing low melting point alloy utilizing fused deposition (FDM) modelling technique
(Springer, 2024-10) Kala, Prateek
3D printing techniques are now effectively utilized for various applications, including medical, electronics, tooling, etc. One such application is the direct printing of electronic circuitry or machine tool using low melting point alloys like solder. The most common solder material is the alloy of tin and lead. However, lead is now being replaced with other elements like copper, silver, bismuth, etc., due to its hazardous nature. The current study uses fused deposition modelling to highlight the deposition of Sn-Bi, a low melting point alloy. The customized direct-type extruder head is fitted to an existing FDM printer to achieve the required deposition. The idea behind using direct type extruder assembly instead of bourdon type is to get the necessary force for pushing the metal out of the nozzle. The process window of temperatures is identified for extruding the material and suitable print speed for depositing the same. The discontinuity is observed at a particular range of parameters and filament types. The filament combinations of 1.75 and 2.85 mm are used with subsequent modifications in the extruder assembly. The nozzle diameter is varied with two filament combinations. The results for both filament types are compared in terms of continuity and uniformity in the deposition. The microstructure of the raw material and deposited beads are also analyzed. The future scope of the current setup can be its utilization for printing electronic circuits or developing a tool for rapid tooling applications.
Experimental investigations into internal magnetic abrasive finishing of pipes
(Springer, 2016-05) Kala, Prateek
Surface finish is one of the important parameters that affects functional aspects of an assembly like friction between mating parts and wear resistance. Magnetic abrasive finishing is one of the advanced finishing processes which has the ability to produce nano-finished surface by removing material in the form of microchips. The present paper introduces a novel tool based on magnetic abrasive finishing (MAF) principle for polishing holes, blind holes, grooves, and vertical surfaces. The tool designed and developed in the present study consists of two permanent magnets with their similar pole facing each other, such that a high magnetic flux density is achieved around the circumferential area between the magnets and the same has been simulated using Maxwell software. In order to evaluate the performance of the tool, experimentation based on central composite design (CCD) technique was performed to finish stainless steel (SS304) pipe. The results so obtained were analyzed to study the effect of process parameters like rotational speed, magnetic flux density, abrasive size, and abrasive weight percentage on percentage change in surface roughness. The analysis showed that the magnetic flux density was the most effective parameter while finishing the stainless steel (SS304) pipe followed by rotational speed. Experimentation at an optimized condition resulted in a surface finish of 56 nm. Further SEM images were taken to understand the surface morphology of finished surface.
Experimental investigations into ultrasonic-assisted double-disk magnetic abrasive finishing of two paramagnetic materials
(Sage, 2015-05) Kala, Prateek
This article evaluates the finishing performance of ultrasonic-assisted double-disk magnetic abrasive finishing process on two paramagnetic materials (copper alloy and stainless steel) with different mechanical properties such as flow stress, hardness, shear modulus, and so on. The finishing experiments were performed based on response surface methodology. The results obtained after finishing have been analyzed to determine the effect of different process parameters such as working gap, rotational speed, and pulse-on time of ultrasonic vibration for both work materials and to study various interaction effects that may significantly affect the finishing performance by the process. The outcome of analysis for the two different work materials has been critically compared to understand the effect of the considered process parameters on the finishing performance of the process based on mechanical properties of the workpiece such as hardness. Furthermore, the scanning electron microscopy and atomic force microscopy were carried on the workpiece surface to understand the possible mechanism of material removal and the surface morphology produced after the finishing process.
Experimental investigations of chemo-ultrasonic assisted magnetic abrasive finishing process
(Inder Science, 2015-12) Kala, Prateek
Chemo-ultrasonic assisted magnetic abrasive finishing (CUMAF) is a compound finishing process, which integrates the use of chemo-mechanical polishing (CMP), ultrasonic vibrations and magnetic abrasive finishing (MAF), to finish surfaces up to nanometre order within a short span of time. The present work is focused on design and fabrication of experimental set up to perform CUMAF. Using the developed set up, experiments were conducted on copper alloy work piece and the effects of five process parameters on percentage change in average surface roughness value (ΔRa) was recorded. The experiments were planned using response surface methodology. Experimental data were analysed using analysis of variance to understand contribution of various process factors and interactions on process response. Regression model was developed to predict the percentage change in surface roughness in terms of significant process factors and interactions. Further the developed model was validated and optimised using genetic algorithm to maximise the performance of the developed process
Experimental investigations of TIG welding based additive manufacturing process for improved geometrical and mechanical properties
(IOP, 2019) Kala, Prateek
The welding based additive manufacturing process has a potential for producing functional 3D metallic component in a cost effective manner. Out of many welding based alternatives available TIG (Tungsten Inert Gas) based additive manufacturing process is one of the efficient processes. This article aims at developing TIG welding based additive manufacturing process for producing metallic parts with improved geometrical and mechanical properties. In this work authors have identified a process parameter condition by which components with good geometrical properties can be produced. The work reports least bead width deposited, for 1.2 mm filler wire, using wire arc based additive manufacturing system. The study performed on residual stress analysis of the deposited material showed compressive residual stresses throughout the sample. Usually welding process produces tensile stresses in the specimen which may reduce the product life. The compressive stresses reported in this study are considered good as they tend to increase product life. Authors have also addressed the reason for this unusual but favourable behaviour. This work would also help to develop automated TIG welding based metal deposition system to produce thin walled structures with improved mechanical and geometrical properties.
Experimental study on finishing forces in double disk magnetic abrasive finishing process while finishing paramagnetic workpiece
(Elsevier, 2014) Kala, Prateek
Knowledge of finishing forces is important in any manufacturing process as the surface integrity of the finished surface is being affected. In the present work finishing force and torque were measured for a recently developed double disk magnetic abrasive finishing process. Investigations have been made to understand the effect of process factors namely upper and lower working gap rotational speed, abrasive weight percentage on the normal finishing force and finishing torque. Experiments were planned and performed based on Taguchi L9 orthogonal array. Analysis of variance has been used to analyze the experimental data. The analysis of the experimental data showed that normal finishing forces is affected most significantly by lower and upper working gap and finishing torque is effected mostly by the lower working gap and rotational speed of the magnetic disk. The surfaces finished by DDMAF process are characterized by SEM and the surface morphology has been correlated to finishing force and torque values.
Feasibility study of fusible alloy-based copper electroplated EDM tool for biomedical applications
(Springer, 2024-10) Kala, Prateek
The current study demonstrates the idea of making customised EDM tools using low melting point alloys for possible application in surface modification of biomedical implants. The mould is 3D-printed through a selective laser sintering setup and is used for casting the eutectic tin bismuth alloy. The mould is 3D scanned before and after using it as a mould for inspecting dimensional accuracy. The mould and cast pattern are measured for their surface roughness. The electroplating setup is developed, plating parameters are identified for stable copper deposits on a cast pattern, and thickness is noted with time. The scanning electron microscope analyses the microstructure of the casted and plated sample. The X-ray diffraction test and energy dispersive spectroscopy verify their composition. The plated sample is used as an electrical discharge machining tool. The planned experiments are performed, and Taguchi optimisation is carried out. The rapid cast tool performance is comparable to the solid copper tool. The valuable insights are drawn out after analysing the results, and the mechanism is explained. The previous research work done in this regard consists of the polymer base material with subsequent primary and secondary metallisation. However, the current study utilised the conductive base material, which eliminates the need for primary metallisation. The current work's application is defined in terms of creating a free-form EDM tool for surface modification of the Ti–6Al–4V femur bone implant for better cell growth.
In chamber calibration and performance evaluation of air quality low-cost sensors
(Elsevier, 2024-12) Kala, Prateek
Assessing individual exposure to PM2.5 (particulate matter of aerodynamic diameter lesser than 2.5 μm) requires precise monitoring of PM2.5 concentrations at specific geographical and temporal scales. This demand is met globally by low-cost particulate matter sensors, although calibrating them is difficult. In this study, four low-cost PM sensors, Sharp GP2Y1010AU0F, Honeywell HPMA115S0-XXX, Plantower PMSA003-A, and Sensirion SPS30, were calibrated and tested using various aerosols. The calibration method has three steps: individual (considering each sensor independently to a single aerosol type; n = 1), combined (all sensors for a specific model together for a specific aerosol type; n = 4), and generic (all sensors for a given model together to all aerosols; n = 16). Sensor responses are processed using linear, quadratic, power-law, and artificial neural network (ANN) algorithms in each calibration stage. Performance metrics, including coefficient of determination (R2), mean absolute percentage error (MAPE), root mean square error (RMSE), and percentage coefficient of variation (% CV), were utilized for assessment. Amongst all the four tested sensors, the Sensirion SPS30 sensors gave the best performance with a minimum R2 value of 0.911 when calibrated with a generic ANN calibration algorithm. Also, the MAPE was less than 10 %, and the RMSE was less than 7 % when exposed to different particles. Sensirion SPS30 showed the lowest inter-sensor variability with % CV less than 6 %. Sensors identified monodisperse polystyrene latex (PSL) particle size in the investigation. Regardless of exposure to 0.3, 0.46, 0.60, or 1.0 μm PSL, the reported number size distribution for the PMSA003 sensor remained consistent and did not align with the results from Grimm. As the PSL size rose, the SPS30 size distribution changed towards larger particle sizes, although it did not always match Grimm data. As the PSL size increased, the sensor's PM1, PM2.5, and PM10 mass proportions altered.
Investigating into casting LMPA (low-melting-point alloy) with 3D-printed mould and inspecting quality using 3D scanning
(Emerald, 2024-07) Kala, Prateek
Three-dimensional (3D) casting means using additive manufacturing (AM) techniques to print the mould for casting the cast tool. The printed mould, however, should be checked for its dimensional accuracy. 3D scanning can be used for the same. The purpose of this study is to combine the different AM techniques for 3D casting with 3D scanning to produce parts with close tolerance for preparing electrical discharge machining (EDM) electrodes.