Tip Size Research Articles

Test parameter and material dependence of the frictional properties of core-shell nanostructure textured surfaces

The friction behavior of core-shell nanostructure textured surfaces (CSNTSs) was systematically studied using indenters of various tip radii under several normal loads. The effects of the test parameters were investigated on two shell materials to elucidate friction mechanisms. The test parameters, material type, texture uniformity, and deformation had a significant impact on friction values. At the lowest load, adhesion led to the highest coefficient of friction (COF) on both surfaces for all tip sizes tested. At low contact pressures, the Al/diamond-like carbon (DLC) CSNTS experienced a lower COF than the Al/amorphous silicon (a-Si) CSNTS due to DLC has better tribological property than a-Si. At higher contact pressures, more severe deformation and thus higher COF occurred on the Al/DLC CSNTS.

Optimization of Phacoemulsification Tip Gauge on the Oertli CataRhex3 in an in vitro Setting.

PurposeTo evaluate the effect of each of the tip sizes available for the Oertli CataRhex3® phacoemulsification machine on efficiency.MethodsPorcine lenses were fixed in formalin for 2 hours, then cut into 3.0 mm cubes. We studied three Oertli tips, all of which had a 30-degree bevel: easyTip 2.2 mm (20G), easyTip 2.8 mm (19G), and CO-MICS (21G). For the 19G and 20G tips, vacuum was set at 600 mmHg, irrigation rate at 50 mL/min, continuous power 70%, and bottle height 85 cm. For the 21G tip, vacuum was set at 450 mmHg; irrigation and power settings were identical to those used for the easyTip tips. We measured time to removal and chatter events to determine efficiency.ResultsResults from 20 trials for each tip showed that the larger the gauge size, the more quickly lens fragments were removed. Chatter events demonstrated an increasing trend with smaller tip gauge. The 19G tip used an average time to fragment removal of 2.8 seconds; the 20G, 3.2 seconds; and the 21G, 4.6 seconds. Increasing tip diameter from 21G to 20G decreased emulsification time by 33% (P = 0.02). Increasing the diameter from 21G to 19G further decreased time to emulsification by 42% (P = 0.003). The 21G tip had a mean 1.4 events/cube; 20G, 0.35 events; and 19G, 0.1 events. Differences in mean chatter events for each tip were each statistically significant.ConclusionThese data suggest that when evaluated by chatter events and emulsification time, the 2.8 mm (19G) easyTip proves to have greatest efficiency.

Prediction of the Interface Deformation of Ultrasonic Spot Welding of Multilayer Metal Foils Considering Energy Gradient

Abstract The ultrasonic spot welding (USW) is widely used in the joining of multilayer Cu or Al tabs in the lithium-ion battery. Due to the high-frequency vibration of the sonotrode and various deformation in each interface, the friction behavior is complex which makes it difficult to simulate the welding process of multilayer specimens. In this paper, an efficient and accurate finite element model (FEM) was proposed via introducing the interface heat flux to equivalent the heat generation by the friction. The total heat flux was determined by the heat transfer analysis and the proportion of each interface was determined based on the analysis of the friction behavior. Then, the FEM was validated by comparing the simulated temperature and deformation with experimental results. Finally, the FEM was applied to simulate the USW process of four, five, and ten layers of copper and aluminum foils in order to characterize the gradient of the ultrasonic energy. It was found that the heat generation concentrated in middle interfaces was 65% of the total in the welding of four-layer copper foils. The heat generation was mainly related to the welding parameters and the proportion was related to the size of tips and the structure of specimens. The plastic strain varied in specimens because of the gradient of the input energy. It was most obvious in the welding of 10-layer aluminum foils that the maximum equivalent plastic strain (PEEQ) in the fifth interface was 92.9% smaller than the top interface.

Impact of Radial Lands on the Reduction of Torque/Force Generation of a Heat-Treated Nickel-Titanium Rotary Instrument

This study investigated the impact of a one-sided radial-landed cross-sectional design of a heat-treated nickel-titanium rotary instrument (JIZAI, MANI, Japan; JZ) on torque/force generation and canal-shaping ability, using an experimental non-landed instrument (non-landed JZ) for comparison. Both instruments had tip sizes of 25 and 0.04 or 0.06 taper and were similar in metallurgy and geometry, except for the presence/absence of a radial land. Twenty J-shaped simulated resin canals were instrumented in a two-instrument single-length sequence using an automated root canal instrumentation device with a torque/force analyzing unit. Pre- and post-instrumentation images of the resin canals were analyzed for canal-centering ability at 0–3 mm from the apex. The mean centering ratio was not significantly different between JZ and non-landed JZ (p > 0.05). In the 2nd instrumentation, JZ showed a significantly smaller torque compared with the non-landed JZ (p < 0.05). Regardless of instrumentation sequence, JZ showed a significantly smaller maximum upward force, representing screw-in force (p < 0.05), and a larger maximum downward force (p < 0.05) than the non-landed JZ. JZ generated smaller screw-in forces and had similar canal-centering ability compared with the non-landed JZ.

3D Printing of Meat Following Supercritical Fluid Extraction.

With the spread of COVID-19, understanding the spread of food poisoning, managing food materials related to chronic diseases, food ingredients’ reliability, and non-face-to-face or untact delivery methods are rapidly emerging. A new field of meat research has been introduced for hygienic and healthy recipes to maintain freshness and control personalized ingredients using supercritical processes and 3D printing technology. Supercritical fluid extraction processes (SCF) and untact 3D printing technology will replace traditional meat freshness assessment based on color change according to the degree of oxidation of myoglobin in meat. SCF processes safely and quickly remove residual blood from meat and control fat and cholesterol that may be harmful to the human body. SCF-processed, high-viscosity meats are printed remotely through repeated IoT system variable experiments in WEB-CLOUD between UTEP in Texas, USA, and Korea University in Seoul, Korea. The SCF process in this study confirmed a weight reduction of 8.5% to 22.5%, depending on the temperature, pressure, and SCF process time. Under conditions of a tip size of 1.0 × 10−3 m, a shear rate of 200/s, and a maximum pressing force of 170 N, a 1000 cm3 SCF-processed meat was successfully 3D printed at the other site by transmitting G-code through web.

Об использовании пазов для моделирования трещин при ультразвуковой дефектоскопии

An analysis of the possibility of a rigorous theoretical solution of the three-dimensional problem of elastic wave scattering at the tip of a vertical crack in a welded joint was carried out. It was shown that in the general case of ultrasound scattering on a flat target, the three-dimensional problem can be reduced to a two-dimensional one. On this basis, for an arbitrary direction of sounding a crack in a weld, the dependence assessment of the signal from the crack tip on the direction to the receiver was made. It is noted that the wave size of the crack tip is much smaller than the wave size of the notches tip that can be machined to simulate defects in welded joints. As a result, it is shown that the nature of the scattering of elastic waves at the tip of the crack differs from the nature of scattering on the notches, including in cases where the opening of the notches is minimal based on the possibility of their manufacture. The results of an experimental verification of the obtained theoretical estimates on steel and aluminum samples were presented. It was shown that, in contrast to the tip of the cracks, at the tips of the notches, even with their minimal openings, conditions are created for the formation of a scattered field by the type of specular reflection from a volumetric cavity - a side cylindrical reflector.

On Use of Slots in Modelling Cracks in Ultrasonic Testing

The possibility of a rigorous theoretical solution of the three-dimensional problem of scattering of elastic waves at the tip of a vertical crack in a weld is analyzed. It is shown that in the general case of ultrasound scattering on a flat target, the three-dimensional problem can be reduced to a two-dimensional one. On this basis, for an arbitrary direction of sounding a crack in a weld, the dependence of the signal from the crack tip on the direction to the receiver was assessed. It is noted that the wave size of the crack tip is much smaller than the wave size of the end of the grooves that can be made to simulate defects in welded joints. As a result, it was found that the nature of the scattering of elastic waves by the tip of the crack differs from the nature of scattering on the grooves, including in cases where the opening of the grooves is minimal, based on the possibility of their manufacture. The results of an experimental verification of the obtained theoretical estimates on samples of steel and aluminum are presented. It is shown that at the ends of the grooves (in contrast to the crack tips), even with their minimal openings, conditions are created for the formation of a scattered field of the type of specular reflection from a volumetric cavity—a side-drilled hole.

Observation of ground surface roughness values obtained by stylus profilometer and white light interferometer for common metal materials

To find some practical understandings and to derive some rules for roughness calibration for common metal materials, this paper counts surface roughness on 50 ground workpieces of five different materials obtained by a stylus profilometer (here‐in‐after, ‘SP’) and a white light interferometer (here‐in‐after, ‘WLI’). The materials include iron, stainless steel, 45 steel, copper and aluminium on which hardness values are widely ranged. The results show that SP measurement result is generally smaller than WLI measurement result for its stylus tip size and scratches on surface. The SP method has obvious scratches on soft materials (Al and Cu), which leads to the reduction of low spatial frequency information on the measured profile. WLI measurement result is more accurate when measured surface is smooth while SP is more suitable for rough and hard surface roughness measurement.

The effect of the NiTi alloy modification and the taper of endodontic instruments on the cyclic fatigue resistance

Background/Aim: The fracture of engine-driven instruments during root canal treatment has been tried to be eliminated by developing the manufacturing process of the files. The aim of this study was to assess cyclic fatigue resistance (CFR) of the two different rotary filesEdgeSequel™ Sapphire (ES) and Race® Evo (RE)which are produced by two different manufacturing technologies. Material and Methods: While RE is manufactured from heat-treated NiTi alloy with the electropolished surface, ES undergoes a non-disclosed thermal treatment called FireWire heat treatment. The CFRs of ES and RE comprising of similar tip size and taper (15/.04 and 25/.04) were compared on a cyclic fatigue device with an artificial stainless-steel canal (60° curvature, 5 mm radius, 1.5 mm width, and 3.0 mm depth). The continuous water spray with a syringe at 35.5°C was used to decrease the friction and to simulate in vivo conditions. All procedures were performed at recommended speed and torque for both files until fracture occurred. The time to failure (TF) was recorded and the number of cycles to failure (NCF) was calculated. The Weibull calculations (Weibull modulus, R2, predicted cycles, and time for 99 % survival) for NCF and TF were also done. The data were statistically analyzed with the independent two-sample t-test and the paired two-sample t-test. The significance level was set at p < 0.05. Results: Both ES and RE showed a better CFR in 15/.04 tip size than 25/.04 (P < 0.05). The TF of the ES were higher than the RE (P < 0.05). The highest and lowest Weibull modulus values were obtained with RE 15/.04 and RE 25/.04, respectively. Conclusions: Both the tip diameter and alloy modification of the instruments affected the CFR. FireWire heat treatment was associated with longer TF. The bigger the tip diameter, the lower the CFR for both tested products.

Enhancement of Magnetic Vortex Acceleration by Laser Interaction with Near-Critical Density Plasma inside a Hollow Conical Target

The effects of magnetic vortex acceleration (MVA) are investigated with two-dimensional particle-in-cell (PIC) simulations by laser interaction with near-critical density (NCD) plasma inside a hollow conical plasma. Energetic and collimated proton beams can be accelerated by a longitudinal charge-separation field. Energetic protons with a peak energy of 220 MeV are produced in PIC simulations. Compared with a uniform NCD plasma, both the cutoff energy and collimation of proton beams are improved remarkably. Furthermore, the influence of different gap sizes of cone tip is taken into account. For optimizing magnetic vortex acceleration, the gap size of the cone tip is suggested to match the focal spot size of laser pulse.

Flow synthesis of photocatalytic semiconductor-metal hybrid nanocrystals.

Semiconductor-metal hybrid nanostructures are promising materials for photocatalytic applications, providing high efficiencies compared to their composing counterparts. So far, the synthesis of such hybrid nanoparticles was limited to batch reactors, achieving tunability while demonstrating how each of the nanocrystals' characteristics affects photocatalytic performances. Yet, new methodologies should be established to increase the synthetic yield while maintaining high control over the resulting structures. Herein, scalable advanced flow techniques are introduced, yielding ZnSe-metal hybrid nanoparticles either in a thermal growth or photo-induced growth regime. Firstly, thermal gold growth in the flow reactor is achieved with good control over the metal tip size and the nanoparticle morphology. We address the dependence of the reaction on temperature, the precursor to nanorod molar ratios, and additional parameters. Additionally, light-induced growth by the flow reactor is demonstrated for platinum clusters. The quality of the resulting hybrids is directly demonstrated by their functionality in photocatalytic hydrogen generation by water reduction, displaying enhanced activity compared to bare ZnSe nanorods. The fairly straightforward adaptation of such powerful flow-reaction techniques to scale-up photocatalytic hybrid nanoparticle syntheses takes them one step forwards towards the realization of their potential in real-life application scenarios.

Effect of autoclave sterilization on cyclic fatigue of EdgeTaper platinum and ProTaper gold nickel–titanium rotary instruments: An in vitro study

Introduction: The heat during autoclave process affects the fracture resistance of the nickel–titanium rotary file and might exert some effect on its mechanical properties. This study aimed to evaluate the effect of autoclave sterilization on cyclic fatigue of EdgeTaper Platinum® and ProTaper Gold®.Materials and Methods: Forty new files from EdgeTaper Platinum® and ProTaper Gold® rotary files with a #25 tip size were used in this study. Each system was subdivided into four groups according to the sterilization cycle; Group 1: No sterilization, Group 2: Two cycles of sterilization, Group 3: Five cycles, and Group 4: Ten cycles. Cyclic fatigue was evaluated using an artificial stainless steel canal with 60° of curvature and 5 mm radius of curvature at 37°C. The number of cycles to failure (NCF) was calculated and compared using Kruskal–Wallis test and Mann–Whitney U-test. The surface of the fractured file was evaluated with scanning electron microscopy.Results: There were significant differences within the two file brand subgroups regarding the NCF (P > 0.05). ProTaper Gold® also revealed no significant differences in NCF (P > 0.05) related to the sterilization conditions. In addition, EdgeTaper Platinum® showed significantly higher cyclic fatigue resistance than ProTaper Gold® in all groups of this experiment (P < 0.05). The fractured plane showed typical features of cyclic fatigue failure for all instruments.Conclusion: Autoclave sterilization did not affect cyclic fatigue resistance of both EdgeTaper Platinum® and ProTaper Gold® in all groups of the experiment. When compare in each group of this experiment, EdgeTaper Platinum® exhibited higher cyclic fatigue resistance than ProTaper Gold®.

Carbon nanospike coated nanoelectrodes for measurements of neurotransmitters.

Carbon nanoelectrodes enable the detection of neurotransmitters at the level of single cells, vesicles, synapses and small brain structures. Previously, the etching of carbon fibers and 3D printing based on direct laser writing have been used to fabricate carbon nanoelectrodes, but these methods lack the ability of mass manufacturing. In this paper, we mass fabricate carbon nanoelectrodes by growing carbon nanospikes (CNSs) on metal wires. CNSs have a short, dense and defect-rich surface that produces remarkable electrochemical properties, and they can be mass fabricated on almost any substrate without using catalysts. Tungsten wires and niobium wires were electrochemically etched in batch to form sub micrometer sized tips, and a layer of CNSs was grown on the metal wires using plasma-enhanced chemical vapor deposition (PE-CVD). The thickness of the CNS layer was controlled by the deposition time, and a thin layer of CNSs can effectively cover the entire metal surface while maintaining the tip size within the sub micrometer scale. The etched tungsten wires produced tapered conical nanotips, while the etched niobium wires were long and thin. Both showed excellent sensitivity for the detection of outer sphere ruthenium hexamine and the inner sphere test compound ferricyanide. The CNS nanosensors were used for the measurement of dopamine, serotonin, ascorbic acid and DOPAC with fast-scan cyclic voltammetry. The CNS nanoelectrodes had a large surface area and numerous defect sites, which improved the sensitivity, electron transfer kinetics and adsorption. Finally, the CNS nanoelectrodes were compared with other nanoelectrode fabrication methods, including flame etching, 3D printing, and nanopipettes, which are slower to make and more difficult for mass fabrication. Thus, CNS nanoelectrodes are a promising strategy for the mass fabrication of nanoelectrode sensors for neurotransmitters.

Use of heat transfer search algorithm while optimizing the process parameters of ECDM to machine quartz material

Electrochemical discharge machining (ECDM) provides an effective means to machine materials which shows poor machinability such as glass, carbon fiber, composites, and silica reinforced composites. This paper focuses on optimization of process parameters of ECDM using a non-conventional optimization technique while machining quartz analysis of the effects of variables on the objective function. Micro size holes were generated using tungsten tool with tip size approximately 800 µm. Controlled parameters considered were Feed rate, electrolyte concentration and voltage, while other parameters are kept constant. The design of experiment was done using Box Behnken type response surface methodology. The objective was to maximize the rate of material removal and minimize the rate of tool wear. Optimization was performed such that multiple set of optimal parameters were obtained and any of the obtained results could be adopted as per the required criteria.

Resistive‐pulse Sensing of DNA with a Polymeric Nanopore Sensor and Characterization of DNA Translocation

AbstractThe ability to detect DNA strands and determine their characteristics in solution plays a critical role to design a sensor in terms of its biophysical properties and receives attention in whole‐ genome sequencing. In this study, we report a simple method to detect 100‐bp DNA based on resistive‐pulse sensing and its characteristics in terms of analyte concentration, potential, tip size. and electrolyte concentration. Track‐etched polyethyleneterephtalate (PET) nanopores were used and modified (w/EDC‐NHS coupling) to decrease the negative surface charge and promote DNA translocation. We tuned up the tip diameters of nanopores by using symmetric and asymmetric chemical etching. The tip diameters ranged from 21 nm to 42 nm. To show the electrophoretic nature of translocation, we investigated the concentration and potential dependence. The current‐pulse events were observed down to 600 mV (4±1 events/min) and 0.25 nM was the minimum concentration. Both potential and concentration dependence showed linear behavior which agreed to previous studies. The effect of tip size was also studied and its effect on translocation frequency was discussed. Finally, the change in current‐pulse amplitude and duration as a function of electrolyte concentration was studied and longer duration values (14.3±1.4 ms) were observed. Our findings provide a guide to translocate the charged molecules more efficiently and help to understand the translocation dynamics of short DNA molecules in resistive‐pulse sensing.

Evaluation of the effect of Irritrol as final irrigant against Staphylococcus epidermidis: an in Vitro Study

Background and Objective: Endodontic infections are considered to be caused by the presence of various microorganisms within the root canal system. Staphylococcus epidermidis is one of the most isolated or detected species from oral infections, including marginal periodontitis, infected root canals, peri‐radicular, peri‐implantitis, and also detected in cases of failed endodontic therapy. In order to prevent endodontic treatment, failure irrigation is mandatory for the effective removal of smear, pulp tissue, smear layer, and microorganisms. The objective of the current study is to evaluate and compare the effect of Irritrol with other final irrigants regarding disinfecting root canal from S. epidermidis. Methods: Fifty‐five single roots premolars with single canals were selected. All of the samples were infected with standard strains of Staphylococcus Epidermidis. Samples were randomly divided into five groups, and five teeth were put as a control group to be compared to the samples after disinfection. Each group consisted of 10 samples according to the type of final irrigants used during and after instrumentation: 5.25% NaOCl/ Irritrol as final irrigant G2 NaOCl 5.25% / NaOCl 5.25%, G3 Normal Saline, G4 Irritrol with activation, G5 NaOCl with activation. All samples were prepared and instrumented by using ProTaper NEXT rotary system till X3. 5.25% NaOCl was applied with a 27‐G double side‐vented syringe needle as an initial irrigant then followed by the final irrigants. Ultra X ultrasonic device was used for the activation of irrigation with a high degree of 45,000 kHz and using tip size 20# with taper of 2%. CFU of each sample was counted before irrigation regime and after the irrigation regime, and they were compared to the control group. Results: In decreasing the amount of bacteria colonies G4 (Irritol with activation) 94% and G5 (NaOCl 5.25%), 92% of the CFU were decreased compared to the control group. Whereas, in Group 3 (Normal Saline) had the least effect on the CFU count decrease. In group 1 (Irritrol) and G2 without activation. Irritrol had less effect than NaOCl 5.25% in the amount of eliminating bacteria count. Conclusion: Irritrol, NaOCl 5.25% with the aid of PUI, can eliminate a significant amount of bacteria in the root canal. In the future, irritrol might be able to be a promising antibacterial irrigant as well as a chelating agent.

Pro tip: Screen-based payment methods increase negative feelings in consumers but do not increase tip sizes

Leaving monetary tips for servers is a commonplace occurrence in the United States. Tipping research has proposed that consumers tip to serve a variety of motives such as to ensure good service on future patronage, supplement servers’ wages, and comply with social norms. Meanwhile, research on environmental factors that affect tipping behavior, such as method of bill payment, have yielded mixed findings. The advancement of technology has increased the use of screen-based payment methods that feature options with differing suggested tip amounts. This technology may pressure consumers into leaving larger tips or start tipping in situations where they previously would not. Using a computer-based study, we simulated limited-service experiences where customers have short interactions with their servers (e.g., ordering a cup of coffee to-go at a coffee shop). We studied how the availability of screen-based payment methods affected consumer feelings about establishments and tip amounts. Results indicated that, in our simulated coffee shop scenario, people feel negatively about screen-based payment methods and may avoid limited-service establishments that use them, but they did not leave larger tips when compared to other payment methods. Moreover, people did not tip more when a server was visible (versus absent) and empathy did not moderate this effect. Together, these findings suggest that people tip to comply with social norms in limited-service environments even if they may feel negatively about the consumer experience.

Influence of Tip Diameter and Light Spectrum of Curing Units on the Properties of Bulk-Fill Resin Composites.

Objective The aim of this study was to evaluate the influence of different light-curing units (LCUs) with distinct tip diameters and light spectra for activating bulk-fill resins. Materials and Methods The specimens ( n = 10) were made from a conventional composite (Amaris, VOCO) and bulk-fill resins (Aura Bulk Fill, SDI; Filtek One, 3M ESPE; Tetric Bulk Fill, Ivoclar Vivadent) with two diameters, 7 or 10 mm, × 2 mm thickness. Following 24 hours of specimen preparation, the degree of conversion (DC) was evaluated using the Fourier-transform infrared unit. Knoop hardness (KHN) readings were performed on the center and periphery of the specimens. Data were assessed for homoscedasticity and submitted to one-way and three-way analysis of variance followed by the Tukey's and Dunnett's tests, depending on the analysis performed (α = 0.05). Results LCUs and specimen diameter significantly affected the DC. The Tetric Bulk Fill provided increased DC results when light-cured with Valo (54.8 and 53.5%, for 7 and 10 mm, respectively) compared with Radii Xpert (52.1 and 52.9%, for 7 and 10 mm, respectively). No significant differences in KHN results were noted for the conventional resin composite ( Amaris ) compared with LCUs ( p = 0.213) or disc diameters ( p = 0.587), but the center of the specimen exhibited superior KHN ( p ≤ 0.001) than the periphery. Conclusion The light spectrum of the multipeak LCU ( Valo ) significantly increased the DC and KHN of the bulk-fill resin composite with additional initiator to camphorquinone ( Tetric Bulk Fill ) compared with the monowave LCU ( Radii Xpert ). The tip size of the LCUs influenced the performance of some of the resin composites tested.

Influence of pecking frequency at working length on the volume of apically extruded debris: A micro-computed tomography analysis

Background/purposeThere is no consensus to date on how many repetitive pecking motions at working length (WL) should be regarded as optimal during instrumentation. Therefore, this study aimed to evaluate the effect of pecking frequency at WL on the volume of apically extruded debris using three single-file systems in curved, oval-shaped canals. Materials and methodsForty-five single-rooted mandibular premolars with curved, oval-shaped canals were prescanned by micro-computed tomography, anatomically paired-matched, and randomly divided among three groups (n = 15 each): Reciproc Blue (RB), WaveOne Gold (WOG) and XP-endo Shaper (XPS). Samples were embedded in agarose gel to collect extruded debris. After preparation to the WL, each sample was rescanned after one, two, four, 10, and 20 pecking motions at WL, respectively. The debris volume was innovatively calculated by a modification of an existing method using micro-computed tomography. The apical preparation size was also measured. Data were compared using a two-way repeated-measures analysis of variance. ResultsAll single-file systems extruded debris apically, irrespective of the pecking frequency at WL. The extruded debris volume correlated positively with the minor foramen size (P < 0.05); both increased with pecking frequency for each single-file system (P < 0.05). The minor foramen size corresponded to the instrument tip size when reaching the WL once. ConclusionTo produce less debris extrusion and obtain a predictable foramen size corresponding to the instrument tip size, a single pecking motion may be preferred when using single-file systems. Caution should be exercised when applying the current results to clinical situations.

Investigation of tool wear in alumina micromachining by multi-tip ECDM

ABSTRACT Experimental analysis of tool wear in alumina micromachining by multi-tip Electrochemical Discharge Machining (ECDM) technique is reported. Multi-tip tool electrodes having a tip size of 300 µm and length of 10 mm are created in stainless steel by wire-EDM. Experiments are conducted at different tool feed rates, i.e., 0.25 µm/s, 0.50 µm/s, 0.75 µm/s. Tool wear of 3 × 3 array electrode is categorized into three different zones, i.e., outer-most tip, outer-middle tip wear, and central-tip. The experimental results reveal that the outer-most tips are worn out rapidly compared to other tips due to the localization of higher current density and easier availability of fresh electrolytes. The tool wear is severe at a slower feed rate due to prolonged exposure to the higher temperature generated during the ECDM. However, at a higher tool feed rate (≥0.50 µm/s), the tool-tips are in physical contact with the alumina substrate. The central tip has a sideways bending beyond tool travel of 400 µm that would have led to the breakage of thin alumina substrate. The experimental results are useful in understanding the tool wear pattern in multi-tip electrodes during the ECDM process used in the micromachining of alumina and other non-conductive materials.