Laser Cut Research Articles

Origami-Inspired Collapsible Structures for Small Rotorcraft Collision Resilience and Landing

Abstract This article reports on the design, fabrication, and testing of flexible, collapsible structures inspired by origami and kirigami that can be used to protect small rotorcraft from collision impacts and to serve as landing gear. Twenty structures created from variations of Pako Pako, Magic Ball, and Herringbone fold patterns were laser cut from cardstock and evaluated experimentally. Some of the Pako Pako structures were designed to have graduated mechanical stiffness. An empirical procedure based on acceleration measurements has been developed that enables quantitative evaluation of each structure based on the characterization parameters of peak acceleration, peak velocity, translational kinetic energy, impact duration, mass, and mechanical stiffness. Structures were mounted onto the front of a radio-controlled (RC) car and driven on a linear test track into a rigid wall. Accelerations measured during the collisions were numerically integrated to determine velocities over the impact and collapse/compression of the structures. Flight tests conducted with small RC quadcopters demonstrated that the collapsible structures could successfully be used to mitigate collisions, enough to enable the quadcopters to continue flying after a direct impact and to land indoors or on outdoor terrain with varying slopes and surfaces. Based on trade-off comparisons between the evaluative metrics of the cases studied, conical Pako Pako structures with uniform stiffness are shown to be the most effective for collision resilience and landing.

AI Meets Distributed Manufacturing: Wie KI die Verbreitung digitaler Fertigung fördert

Abstract These often use computer-controlled machines like 3D printers and CNC machines. The accessibility of these technologies is increasing, even for non-experts. This leads to widespread use and democratisation of manufacturing technologies, which can support distributed urban production. We present recent developments of an AI-supported laser cutter based on Open Source Hardware (OSH). Our approach integrates machine learning methods, including diffusion-based image generation and Large Language Models. This enables seamless integration of CAD-CAM systems. By combining hands-on learning with OSH machines and digital tools, we ensure a better understanding of the manufacturing workflow. We demonstrate the capability, accessibility, and potential of our approach using OSH machines. This can significantly influence future developments in digital fabrication.

Curved HSIW: an affordable performance for non-planar millimeter-wave applications

This paper introduces a Curved Hollow Substrate Integrated Waveguide (CHSIW) to address the growing demand for millimeter-wave applications, including communication, sensing, imaging, radar, and wireless power transfer systems. Leveraging advancements in integrated circuits and system-in-package (SiP) technology, the CHSIW tackles the challenges associated with hardware integration into curved structures. The design utilizes MultiJet Printing (MJP) for the M3 crystal dielectric substrate and a water laser cutter system for copper sheets, streamlining the fabrication process by eliminating complex via manufacturing steps through prefabricated through-hole vias. Operating in the frequency range of 21.7 GHz to 32 GHz, the CHSIW exhibits outstanding performance on curved surfaces, with measured average attenuation constants of 1.89 Np m−1 (16.42 dB m−1) and 1.95 Np m−1 (16.94 dB/m) for samples with radii of curvature of 166.8 mm and 125.1 mm, respectively. Beyond addressing technical challenges, the CHSIW presents a cost-effective and simplified fabrication process, positioning it as a breakthrough solution for diverse millimeter-wave applications, including future robotic and UAV communications. Furthermore, the proposed design and fabrication technique hold promise for the realization of conformal and free-form Hollow Substrate Integrated Waveguide (HSIW) devices in the future.

Wireless control system for laser cutters and engraving machines

Wireless control system for laser cutters and engraving machines

Hybrid Aerosol Jet Printing and Electrodeposition of Ferrite-Sandwiched Inductors

The additive manufacturing (AM) of inductors of suitable size to be integrated into packaged electronics is attractive to customize the device characteristics for the specific application. Magnetic ferrite cores are widely used in conventional inductors, however, wire wound inductors can be brittle, heavy, bulky. Planar spiral inductors in a sandwich configuration present a promising alternative. Aerosol jet printing, a direct write AM technology, can deposit metal inks at a resolution of < 10 µm. Metal nanoparticle inks have limited conductivity at < 40% bulk. Building a higher profile may result in loss of resolution. Electrodeposition offers the ability to plate thick layers of highly conductive metals, including copper and nickel which are normally hard to access as nanoparticle inks compatible with aerosol jetting. We have previously shown the construction of a multi-layer flyback transformer with this hybrid aerosol jet and electrodeposition method. [1]We present a three-layer planar inductor with the first layer being a 1.3mm stack of ferrite sheets (Fair-Rite) with a 9 mm x 9 mm footprint integrated onto a circuit board. The intermediate layer consists of a spiral inductor made by aerosol jet printing UTDots Ag40X silver nanoparticle ink as the seed layer. To achieve high accuracy, the inductor was printed with a rotary axis stage. Electrodeposition in an acidic CuSO4 plating bath on top of the Ag seed layer resulted in thicknesses of 50 µm. A submicron layer of Ni is added for oxidation protection by electrodeposition from a Ni-Sulfamate bath. Lastly, a top 1.3 mm ferrite stack, with laser cut holes, is added to provide pass throughs for wire bonding. Figure 1 shows a micrograph of an inductor as printed, after electrodeposition, and with the top ferrite layer. Electrical measurements including impedance characteristics will be presented.SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. The SAND No. is SAND2023-14571A.Figure 1. Construction of a ferrite-sandwiched inductor with (a) the aerosol jet printing of an Ag seed layer, (b) after electroplating of Cu and Ni.

Evaluation of In Vitro Serotonin-Induced Electrochemical Fouling Performance of Boron Doped Diamond Microelectrode Using Fast-Scan Cyclic Voltammetry.

Fast-scan cyclic voltammetry (FSCV) is an electrochemical sensing technique that can be used for neurochemical sensing with high spatiotemporal resolution. Carbon fiber microelectrodes (CFMEs) are traditionally used as FSCV sensors. However, CFMEs are prone to electrochemical fouling caused by oxidative byproducts of repeated serotonin (5-HT) exposure, which makes them less suitable as chronic 5-HT sensors. Our team is developing a boron-doped diamond microelectrode (BDDME) that has previously been shown to be relatively resistant to fouling caused by protein adsorption (biofouling). We sought to determine if this BDDME exhibits resistance to electrochemical fouling, which we explored on electrodes fabricated with either femtosecond laser cutting or physical cleaving. We recorded the oxidation current response after 25 repeated injections of 5-HT in a flow-injection cell and compared the current drop from the first with the last injection. The 5-HT responses were compared with dopamine (DA), a neurochemical that is known to produce minimal fouling oxidative byproducts and has a stable repeated response. Physical cleaving of the BDDME yielded a reduction in fouling due to 5-HT compared with the CFME and the femtosecond laser cut BDDME. However, the femtosecond laser cut BDDME exhibited a large increase in sensitivity over the cleaved BDDME. An extended stability analysis was conducted for all device types following 5-HT fouling tests. This analysis demonstrated an improvement in the long-term stability of boron-doped diamond over CFMEs, as well as a diminishing sensitivity of the laser-cut BDDME over time. This work reports the electrochemical fouling performance of the BDDME when it is repeatedly exposed to DA or 5-HT, which informs the development of a chronic, diamond-based electrochemical sensor for long-term neurotransmitter measurements in vivo.

Evaluation of Electrochemical Sensor Using Microfluidic System

This paper presents the characterization and testing of electrochemical sensor using microfluidic system. Various geometric patterns were laser cut into the platinum working electrode of a biosensor. In this work, a microfluidic chamber was designed that allows phosphate buffer solution (PBS) to flow across the sensor, using a peristaltic pump, while varying the concentration of hydrogen peroxide. The amperometric characterization of the electrochemical sensor with 25, 50, 75, and 100[Formula: see text][Formula: see text]m perforation and 75[Formula: see text][Formula: see text]m spacing showed the highest sensitivity. This result was to be expected the purpose of patterning the sensors was to provide a 3-dimensional structure to the planar electrode in order for the enzyme, glucose oxidase, to be immobilized. Future work will include selecting one of the patterns for immobilization of glucose oxidase allowing us to realize a fully functional glucose sensor.

High-Speed Steel Technology Substitution in Mining Machinery – an Experimental Study

The growth of mineral extraction in countries with a developed mineral resource sector under conditions of external restrictions requires the modernization of the domestic mining machinery – an indispensable condition of which is the replacement of technologies for the production of high-speed steels and machine tools. This research was aimed at experimental studies of microstructure, phase composition and microhardness distribution in the surface layer of the R6M5 high-speed steel samples after laser cutting, cold treatment and laser tempering. It was demonstrated that after laser cutting in the surface layer of the cut there was the carbide dissolution and enrichment of the metal matrix with carbon and alloying components, resulting in an increase of residual austenite content up to 50...60 %. After the cold treatment in liquid nitrogen the content of residual austenite decreased up to 7...9 %. The laser cut surface microhardness increased up to 1000...1100 MPa. At further laser tempering the dispersion hardening processes took place, as a result the V2C carbides appeared in the steel structure amounting to 4.7 %. The microhardness increased up to 10400...10600 MPa. The study showed the possibility of using the high-speed steel laser cutting not only as a separating operation, but also as a hardening treatment. The findings contribute to the technological support for the development of domestic mining machinery in terms of replacing imported high-speed steels and machine tools.

Multi-sensor monitoring and analysis of indoor pollutant emissions in response to laser cutter operating conditions

This study analyzed pollutant emissions from laser cutters used in modeling in a laboratory, which can have harmful effects on indoor air quality and health. Four conditions were tested: material thickness, laser cutter strength, minimum strength per thickness, and air purifier level. Four pollutants were analyzed: PM2.5, HCHO, VOCs, and CO2. The study found that the emissions of PM2.5, HCHO, and VOCs increased with paperboard thickness, while CO2 emissions were not significant. PM2.5 was more affected by laser cutting strength, while HCHO and VOCs were more affected by paperboard thickness. Additionally, we analyzed the PM2.5 emission rates based on the thickness of the paperboard and the laser cutting strength. Therefore, emission rates based on thickness and laser cutting strength ranged from 7275 to 18,783 μg/min. The air purifier significantly reduced PM2.5 but not HCHO and VOCs. To reduce these gaseous pollutants, combining mechanical ventilation or using an air purifier with a filter that adsorbs HCHO and VOCs is effective. This study highlights the importance of considering laser cutters as a potential source of indoor air pollutants and implementing measures to mitigate their harmful effects.

Effect of Fiber-Laser Parameters on Cutting Accuracy of Thin and Thick S355JR Structural Steel Plates

Fiber lasers, the latest laser-cutting technology, are notable for their high process efficiency, cutting precision, and high cutting quality for thin materials. However, the quality of the cut significantly decreases when machining thicker materials. For now, this is a challenge for the metalworking industry. This study investigated the effects of laser power, cutting speed, and auxiliary gas pressure on the fiber-laser cutting quality of 4 and 6 mm thick S355JR steel plates. To evaluate the influence of cutting parameters on cutting quality, surface roughness, dimensional accuracy and cut taper were measured. A microscopic analysis of the laser cuts was performed, revealing the heat-affected zone, transition zone and unaffected base-material zone. Research results show that laser cutting is a complex process, and the correct choice of cutting parameters greatly influences the cutting performance and final quality. An artificial neural network was created and trained using the results from measuring the quality characteristics to achieve optimum cutting quality. The accuracy of the optimization model was assessed by control samples, which were cut using calculated optimum parameters. The actual values of the quality characteristics only slightly differ from the predicted values, showing that the optimization model is suitable for selecting cutting parameters.

Novel Cardiovascular Stent Based on Hibiscus-Aestivation-Inspired Auxetic Unit Cell

Conventional stents have some limitations, such as dogboning and foreshortening, that can lead to issues like in-stent restenosis and thrombosis. Negative Poisson's ratio stents, called auxetic stents, are known as a solution to overcome these challenges due to their unique deformation mechanism. Auxetic stents are scale-independent, and their behavior depends solely on their geometry. In this study, a novel auxetic unit cell inspired by aestivation mechanism of the Hibiscus flower is designed, developed, and implemented in plane, and a tube to achieve a novel NPR cardiovascular stent. The stent structure is fabricated using two methods, including a novel 7-axis laser cut method capable of producing stents the same size as human blood vessels from an SS 316 L tube, and fused deposition modelling 3D printing at a scale 20 times larger than the metallic sample using PLA filaments. Novel laser cut effectively overcame some challenges in laser cutting stents, including HAZ and thermal shocks. SEM images are taken from the laser cut sample, and the manufacturing method's accuracy and surface quality are investigated. Fabricated metallic and polymeric stent samples proposed negative Poisson's ratio equal to 0.89 with an average of 4.38 and 14.8% errors, respectively, compared with finite element analysis. Finally, the structure's stress, strain energy distribution pattern, and unit cell distribution have been examined. Furthermore, the stent thickness parameter, drug release patch application, and stent implementation process are also investigated using FEM method. Proposed geometry in stent application showed solutions to conventional positive Poisson's ratio stent challenges.

40‐1: Development of the Auto Monitoring Method of Laser Beam Shape and Size by Employing the AI and Computer Vision Algorithm

The beam shape of the laser cut process to change the display shape is very important in the laser cutting quality, and the laser beam shape was measured by using the beam profiler as a measuring instrument. Since the beam profiler cannot be used due to damage caused by the high laser processing power used in mass production, the beam shape be managed that the sample was created by laser beam cross shot drawing on the material and it was manually measured by using a microscope. However, this method had problems with a long management period (measured once a month), a machine down for the measurement, the measurement deviation between engineers, and inability to manage history, so it was necessary to develop AI‐based shape automatic management technology. To solve this problem, an AI agent program with the AI technology to determine OK, NG of laser beam and the beam size measurement technology based on the image processing was developed and applied to the production line. Through this program, automatic management and history management of beam shape and size that was not possible with previous method have become possible. It was confirmed that the AI and image processing technologies developed through this study can be important technologies that can have a ripple effect on the development of other technologies.

Evaluation of Cutting Parameters on Heat-Affected Zone in Wood Plastic Composites by Pulsed Fiber Laser

Biodegradable and environmentally friendly composite materials such as wood plastic composites (WPCs) have gained attention in industrial applications due to environmental concerns and global sustainability goals. However, owing to their unique structures and properties, cutting on WPCs can be challenging. Continuous wave (CW) mode laser may result in heat build-up and easily warp the WPCs during laser cutting. Therefore, minimizing these defects and determining the cutting parameters that influence the heat-affected zone (HAZ) by pulsed mode laser is essential. In this present work, 1 mm thickness of WPC 30 wt.% of wood fiber (WF) filled with recycled high-density polyethylene (rHDPE) has been experimentally cut by single-mode pulsed fiber laser to evaluate the minimum laser energy required to cut the WPC and the influence of cutting parameters on the HAZ. The HAZ was measured using a digital microscope, and the statistical significance of the cutting parameters to HAZ was determined by analysis of variance (ANOVA). The results confirmed that a minimum linear energy of more than 9 J/mm is required to cut the WPC. It has been found that the cutting speed is the major influence on the HAZ, followed by pulse width. Adequate interaction time by cutting speed and duration of the single-laser pulse also significantly affects the cutting process. The higher gas pressure could minimize the HAZ at the surrounding cutting region of the WPCs. Understanding the influence of these parameters could minimize the thermal effect of HAZ and improve the laser cut quality.

Circumscribing Laser Cuts Attenuate Seizure Propagation in a Mouse Model of Focal Epilepsy.

In partial onset epilepsy, seizures arise focally in the brain and often propagate. Patients frequently become refractory to medical management, leaving neurosurgery, which can cause neurologic deficits, as a primary treatment. In the cortex, focal seizures spread through horizontal connections in layers II/III, suggesting that severing these connections can block seizures while preserving function. Focal neocortical epilepsy is induced in mice, sub-surface cuts are created surrounding the seizure focus using tightly-focused femtosecond laser pulses, and electrophysiological recordings are acquired at multiple locations for 3-12 months. Cuts reduced seizure frequency in most animals by 87%, and only 5% of remaining seizures propagated to the distant electrodes, compared to 80% in control animals. These cuts produced a modest decrease in cortical blood flow that recovered and left a ≈20-µm wide scar with minimal collateral damage. When placed over the motor cortex, cuts do not cause notable deficits in a skilled reaching task, suggesting they hold promise as a novel neurosurgical approach for intractable focal cortical epilepsy.

Sustainable Greeting Card – paper Products Produced on a Laboratory Paper Machine

Paper products have been used for thousands of years for art and communication purposes. The presented project describes the development of a unique greeting card art paper product, comprised of a card stock with a basis weight of 150 g/m2 having a purple color tone and inlay paper product with a basis weight of 100 g/m2. The inlay paper product should have a gras fiber content that is visualized by a tree cut out in the cover paper. The inlay paper should be printable with a standard ink-jet printer as well as be able to write on with a fountain pen. Both paper grades were developed with a hand sheet study and then upscaled to a small 225 mm wide laboratory Fourdrinier paper machine. The produced cover paper and inlay paper had a basis weight of 152.20 g/m2 for the cover paper having a purple color tone and 102.64 g/m2 for the inlay paper, meeting all mechanical and optical properties as required. The finished cover and inlay paper product was converted into DIN A5 and DIN A6 card stock, including cutting out the tree image from the cover paper using a laser cutter.

Optimization of the electrolytic polishing parameters of intravascular stent based on the orthogonal test method

Cardiovascular diseases are the most important global health threat because of their prevalence. Intravascular stent interventional surgery is regarded as the primary treatment method of cardiovascular diseases, so high-performance stents are in great demand. In this study, the influence of key process parameters on the surface properties of the stent was investigated to improve the serviceability of laser cut intravascular stent. Using the test method, the influence of each process parameter on the surface integrity of the support was determined, and then the optimal combination of electrolytic polishing parameters was obtained. On this basis, the quantitative statistics of material removal and the wettability of electrolytic polishing were studied. The results show that the surface quality of the scaffold is the best when the volume ratio of concentrated sulfuric acid and glacial acetic acid electrolyte is 1:11, the polishing temperature is 34 ℃, the polishing voltage is 22 V, the polishing time is 80 s, and the electrode distance is 22 mm. The wall thickness and bridge width of the stent were reduced by 26.99 and 29.34 μm, respectively, and the mean hydrostatic contact angle was increased by 24.35°, which improved the biocompatibility of the stent.

4D-Printed Tool for Compressing a Shape Memory Polyurethane Foam during Programming.

Although several force application concepts are known that can be used to deform shape memory polymers (SMPs) within the scope of programming, controlled deformation is challenging in the case of samples with a cylinder-like shape, which need to be homogeneously compressed starting from the lateral surface. To solve this problem, this contribution follows a material approach that takes advantage of four-dimensional (4D) printing. Fused filament fabrication (FFF) was used as an additive manufacturing (AM) technique to produce a thermoresponsive tool in a cylindrical shape from a polyether urethane (PEU) having a glass transition temperature (Tg) close to 55 °C, as determined by differential scanning calorimetry (DSC). Once it was 4D-printed, a sample of laser cut polyester urethane urea (PEUU) foam with a cylindrical wall was placed inside of it. Subsequent heating to 75 °C and keeping that temperature constant for 15 min resulted in the compression of the foam, because the internal stresses of the PEU were transferred to the PEUU, whose soft segments were completely molten at 65 °C as verified by DSC. Upon cooling to -15 °C and thus below the offset temperature of the soft segment crystallization transition of the PEUU, the foam was fixed in its new shape. After 900 days of storage at temperatures close to 23 °C, the foam recovered its original shape upon reheating to 75 °C. In another experiment, a 4D-printed cylinder was put into hibernation for 900 days before its thermoresponsiveness was investigated. In the future, 4D-printed tools may be produced in many geometries, which fit well to the shapes of the SMPs to be programmed. Beyond programming SMP foams, transferring the forces released by 4D-printed tools to other programmable materials can further expand technical possibilities.

Creation of a Corneal Flap for Laser In Situ Keratomileusis Using a Three-Dimensional Femtosecond Laser Cut: Clinical and Optical Coherence Tomography Features

Laser in situ keratomileusis (LASIK) is the most frequently used technique for the surgical correction of refractive errors on the cornea. It entails the creation of a superficial hinged corneal flap using a femtosecond laser, ablation of the underlying stromal bed using an excimer laser, and repositioning of the flap. A corneal flap with an angled side cut reduces the risk of flap dislocation and infiltration of epithelial cells and confers unique biomechanical properties to the cornea. A new laser software creating three-dimensional (3D) flaps using a custom angle side cut was retrospectively evaluated, comparing optical coherence tomography 3D (with intended 90° side cut) and 2D flaps (with tapered side cuts) as well as respective intra- and early postoperative complications. Four hundred consecutive eyes were included, two hundred for each group. In the 3D group, the mean edge angle was 92°, and the procedure was on average 5.2 s slower (p = 0). Non-visually significant flap folds were found in thirteen eyes of the 2D group and in seven eyes of the 3D group (p = 0.17). In conclusion, the creation of a LASIK flap using a 3D femtosecond laser cut, although slightly slower, was safe and effective. The side cut angle was predictable and accurate.

Solid-Phase Orientation (Die Drawing) of Polymer Tubes to Enhance Mechanical Properties of Bioresorbable Vascular Scaffolds

Die-drawing, also known as solid phase orientation, is a technique used to enhance the mechanical properties of polymers for non-medical applications [1]. Arterius has adapted and optimised this technology to manufacture state-of-the-art bioresorbable polymeric scaffolds (stents) based on polylactic acid (PLA) for vascular and non-vascular applications. The mechanical properties of the polymer are improved by orientating the polymer chains and introducing crystallinity to the polymer. As the PLA polymer is drawn over a mandrel and through a die, close to the glass transition temperature (Tg &gt; 55 °C), the polymer chains align, gradually increasing orientation with the bi-axial draw, thus promoting significantly improved mechanical properties. In-house testing of the die-drawn tubing compared to the extruded tubing showed an increase in tensile modulus up to 79.7%, yield strength increases of up to 121.5%, ultimate tensile strength increases of up to 267.9% and elongation at break increase of up to 1,022.8%. The die-drawing process also introduces crystallinity into the PLLA tubing, initially the amorphous extruded tube has a crystallinity of around 1.3% which increased to around 40% crystallinity after the die-drawn process. Another attribute of the orientated polymer tubing is the radial strength it provides to the scaffold once it has been laser cut into an innovative closed-cell design, which is comparable to market-leading metallic stents.

Microwave hydrogen plasma etching on the laser-cut surface of single crystal diamond: Phases, etching morphology, stress evolution and the effect of etching on the subsequent homoepitaxial growth

In order to improve the pretreating efficiency of single crystal diamond (SCD) before its homoepitaxial growth, a strategy coupling laser cutting and microwave hydrogen plasma etching was proposed to replace the traditional pretreatment steps, which underwent laser cutting, mechanical polishing, acid cleaning, and microwave plasma etching in order. The feasibility of this idea has been studied by growing SCD after directly etching its laser-cut surface using microwave hydrogen plasma. The effect of the etching time on the SCD including surface phase, etching morphology, etching pit shape, residual stress, growth morphology, and quality of SCD are investigated and analyzed. The results show that microwave hydrogen plasma etching can quickly (within 10 min) remove the residual graphite carbon on the SCD surface caused by laser cutting. The extension of the etching time mainly affects the surface morphology and the internal stress of SCD. Etching pits with different shapes (square, trapezoid, inverted pyramid) and sizes can be found on the hydrogen plasma etched surface under different etching times. Fortunately, these etching pits do not introduce polycrystals on the SCD during subsequent homoepitaxial growth. All the hydrogen plasma etched laser cut SCD samples exhibit typical step-flow growth morphology after 20 h of homoepitaxial growth. Moreover, the step-flows are orderly and parallel, which is better than the disorderly step-flows on the polished SCD. Besides, a higher growth quality and a lower residual stress are obtained for the etched SCD. The above results indicate that replacing the traditional complex pretreatment steps with laser cutting and etching pretreatment is feasible. The new approach can effectively improve the pretreatment efficiency and result in superior quality of SCD after homoepitaxial growth.