DESIGN, MANUFACTURING AND PROBLEM ANALYSIS OF AN ENTIRELY FDM 3D PRINTED LINEAR PNEUMATIC ACTUATOR

Urgency of the research. Currently, manufacturing of pneumatic components is reserved only to well-equipped manufacturing plants and machine shops. The ability to reliably manufacture pneumatic components on a FDM 3D printer would enable the creation of low-cost custom-made pneumatic actuators with novel properties. This, in turn, could increase the speed and lower the cost of development of prototypes that use pressure air as their power source. Target setting. Today cost-effective 3D printers can be found both in manufacturing plants and small machine shops andhobbyist workshops. Hawing the possibility to make reliable pneumatic components like pneumatic actuators on such machines could be beneficial and lead to opening new applications for them. Actual scientific researches and issues analysis. Currently most research on using additive manufacturing to construct a pneumatic actuator focuses mainly on bellows type actuators. Research on 3d printing of classical pneumatic actuators is scarce and often presents a rough overview of the design process and immediately presenting a functional prototype without focusing and studying the design hurdles thoroughly. Uninvestigated parts of general matters defining. Parts for firm pneumatic actuators manufactured by FDM 3D printing exhibit properties that have detrimental effects on the optimal working of such actuators. The question is on the magnitude of these effects whether these effects can be tolerated and how to design such a firm pneumatic actuator without the need to postprocess all the components. The research objective. The aim of these research was to manufacture an early prototype of full plastic 3d printed not postprocessed linear actuators and make a preliminary analysis of encountered problems therefore pointing the way for further research in this field. The statement of basic materials. The analysis consists of an attempt to manufacture a simple prototype of full plastic 3d printed linear actuators without the use of postprocessing techniques and establishing a baseline for further research. Conclusions. In this paper the design of three iterations of FDM 3D printed pneumatic cylinders are presented. The problems arising from not using any postprocessing on either of the parts and using only 3d printed parts for the construction is also discussed. In the final chapter the design hurdles for the design and manufacturing of such an actuator are presented..

Download Full-text

Development of a 3D Printed Double-Acting Linear Pneumatic Actuator for the Tendon Gripping

Polymers ◽

10.3390/polym13152528 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2528

Author(s):

Ivan Grgić ◽

Vjekoslav Wertheimer ◽

Mirko Karakašić ◽

Željko Ivandić

Keyword(s):

3D Printing ◽

Fused Deposition Modeling ◽

Testing Machine ◽

Pneumatic Actuator ◽

Tensile Testing Machine ◽

Laboratory Equipment ◽

Testing Procedures ◽

Fused Deposition ◽

Custom Made ◽

3D Printed

The lack of standardization in tissue testing procedures results in a variety of custom-made devices. In the case of the determination of the mechanical properties of tendons, it is sometimes necessary to adapt the existing laboratory equipment for conducting experiments when specific commercial equipment is not applicable to solve issues such as proper gripping to prevent tendon slipping and rupturing, gripping control and manoeuvrability in case of tendon submerging and without contamination of the testing liquid. This paper presents the systematic development, design, and fabrication using 3D printing technology and the application of the double-acting linear pneumatic actuator to overcome such issues. It is designed to do its work submerged in the Ringers’ solution while gripping the tendon along with the clamps. The pneumatic foot valve unit of the Shimadzu AGS-X tensile testing machine controls the actuator thus preventing Ringers’ solution to be contaminated by the machine operator during specimen set-up. The actuator has a length of 60 mm, a bore of 50 mm, and a stroke length of 20 mm. It is designed to operate with an inlet pressure of up to 0.8 MPa. It comprises the cylinder body with the integrated thread, the piston, the piston head, and the gripper jaw. Fused deposition modeling (FDM) has been used as the 3D printing technique, along with polylactic acid (PLA) as the material for 3D printing. The 3D printed double-acting linear pneumatic actuator was developed into an operating prototype. This study could open new frontiers in the field of tissue testing and the development of similar specialized devices for medical purposes.

Download Full-text

A Miniature 3D Printed On-Off Linear Pneumatic Actuator and Its Demonstration into a Cartoon Character of a Hopping Lamp

Actuators ◽

10.3390/act8040072 ◽

2019 ◽

Vol 8 (4) ◽

pp. 72

Author(s):

Christian L. Nall ◽

Pranav A. Bhounsule

Keyword(s):

3D Printing ◽

Weight Ratio ◽

Pneumatic Actuator ◽

Stroke Length ◽

Pneumatic Actuators ◽

Peak Output Power ◽

Piston Head ◽

Cartoon Character ◽

3D Printed ◽

Selective Placement

Although 3D printing has been extensively used to create passive machines and mechanisms, 3D printing of actuators is a relatively new concept. 3D printing of actuators allows greater customization, accelerates the design and development, and consequently saves time and money. We present the design and fabrication of a 3D printed, miniature size, double-acting, On-Off type, linear pneumatic actuator. The actuator has an overall length of 8 cm, a bore size of 1.5 cm, and a stroke length of 2.0 cm. The overall weight is 12 gm and it generates a peak output power of 2 W when operating at an input air pressure of 40 psi ( 275 . 79 kPa). This paper demonstrates novel methods to solve the challenges that arise during fabrication that include: (1) chemical post-processing to achieve airtight sealing and a smooth surface finish, (2) strategic placement of a metallic part within 3D printed plastic for higher strength, (3) design of an airtight seal between the cylinder and piston head, (4) chemical bonding of printed parts using adhesive, and (5) use of a lubricant to reduce friction and improve force generation. The power-to-weight ratio of our actuator is comparable to that of high-end commercial actuators of similar size. The utility of the actuator is demonstrated in a series of jumping experiments with the actuator and by incorporating the actuator into a hopping robot inspired by Disney/Pixar Luxo lamp. We conclude that 3D printed pneumatic actuators combine the high power of pneumatics with the low weight of plastics, and structural strength through the selective placement of metal parts, thus offering a promising actuator for robotic applications.

Download Full-text

Microstructured Surface Plasmon Resonance Sensor Based on Inkjet 3D Printing Using Photocurable Resins with Tailored Refractive Index

Polymers ◽

10.3390/polym13152518 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2518

Author(s):

Nunzio Cennamo ◽

Lorena Saitta ◽

Claudio Tosto ◽

Francesco Arcadio ◽

Luigi Zeni ◽

...

Keyword(s):

Surface Plasmon Resonance ◽

3D Printing ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Optical Sensor ◽

Low Cost ◽

3D Print ◽

Spr Sensor ◽

Resonance Sensor ◽

3D Printed

In this work, a novel approach to realize a plasmonic sensor is presented. The proposed optical sensor device is designed, manufactured, and experimentally tested. Two photo-curable resins are used to 3D print a surface plasmon resonance (SPR) sensor. Both numerical and experimental analyses are presented in the paper. The numerical and experimental results confirm that the 3D printed SPR sensor presents performances, in term of figure of merit (FOM), very similar to other SPR sensors made using plastic optical fibers (POFs). For the 3D printed sensor, the measured FOM is 13.6 versus 13.4 for the SPR-POF configuration. The cost analysis shows that the 3D printed SPR sensor can be manufactured at low cost (∼15 €) that is competitive with traditional sensors. The approach presented here allows to realize an innovative SPR sensor showing low-cost, 3D-printing manufacturing free design and the feasibility to be integrated with other optical devices on the same plastic planar support, thus opening undisclosed future for the optical sensor systems.

Download Full-text

3D Printed Clamps for In Vitro Tensile Tests of Human Gracilis and the Superficial Third of Quadriceps Tendons

Applied Sciences ◽

10.3390/app11062563 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2563

Author(s):

Ivan Grgić ◽

Vjekoslav Wertheimer ◽

Mirko Karakašić ◽

Željko Ivandić

Keyword(s):

3D Printing ◽

Fused Deposition Modeling ◽

Tensile Tests ◽

Biomechanical Properties ◽

Testing Procedure ◽

Laboratory Equipment ◽

Fused Deposition ◽

Custom Made ◽

3D Printed

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

Download Full-text

Accessing 3D Printed Vascular Phantoms for Procedural Simulation

Frontiers in Surgery ◽

10.3389/fsurg.2020.626212 ◽

2021 ◽

Vol 7 ◽

Author(s):

Jasamine Coles-Black ◽

Damien Bolton ◽

Jason Chuen

Keyword(s):

3D Printing ◽

Endovascular Procedures ◽

Low Cost ◽

3D Models ◽

Routine Care ◽

Aortic Aneurysms ◽

Patient Specific ◽

Ct Angiogram ◽

Abdominal Aortic ◽

3D Printed

Introduction: 3D printed patient-specific vascular phantoms provide superior anatomical insights for simulating complex endovascular procedures. Currently, lack of exposure to the technology poses a barrier for adoption. We offer an accessible, low-cost guide to producing vascular anatomical models using routine CT angiography, open source software packages and a variety of 3D printing technologies.Methods: Although applicable to all vascular territories, we illustrate our methodology using Abdominal Aortic Aneurysms (AAAs) due to the strong interest in this area. CT aortograms acquired as part of routine care were converted to representative patient-specific 3D models, and then printed using a variety of 3D printing technologies to assess their material suitability as aortic phantoms. Depending on the technology, phantoms cost $20–$1,000 and were produced in 12–48 h. This technique was used to generate hollow 3D printed thoracoabdominal aortas visible under fluoroscopy.Results: 3D printed AAA phantoms were a valuable addition to standard CT angiogram reconstructions in the simulation of complex cases, such as short or very angulated necks, or for positioning fenestrations in juxtarenal aneurysms. Hollow flexible models were particularly useful for device selection and in planning of fenestrated EVAR. In addition, these models have demonstrated utility other settings, such as patient education and engagement, and trainee and anatomical education. Further study is required to establish a material with optimal cost, haptic and fluoroscopic fidelity.Conclusion: We share our experiences and methodology for developing inexpensive 3D printed vascular phantoms which despite material limitations, successfully mimic the procedural challenges encountered during live endovascular surgery. As the technology continues to improve, 3D printed vascular phantoms have the potential to disrupt how endovascular procedures are planned and taught.

Download Full-text

Novel 3D-Printed MEMS Magnetometer with Optical Detection

Proceedings ◽

10.3390/proceedings2130783 ◽

2018 ◽

Vol 2 (13) ◽

pp. 783 ◽

Cited By ~ 1

Author(s):

Matthias Kahr ◽

Wilfried Hortschitz ◽

Harald Steiner ◽

Michael Stifter ◽

Andreas Kainz ◽

...

Keyword(s):

3D Printing ◽

Product Development ◽

Rapid Prototyping ◽

Low Cost ◽

High Accuracy ◽

Structural Performance ◽

Sensitivity Measurement ◽

Optical Readout ◽

3D Printed ◽

Working Principle

This paper reports a novel 3D printed MEMS magnetometer with optical readout, which demonstrates the advantages of 3D printing technology in terms of rapid prototyping. Low-cost and fast product development cycles favour 3D printing as an effective tool. Sensitivity measurement with such devices indicate high accuracy and good structural performance, considering material and technological uncertainties. This paper is focusing on the novelty of the rapid, 3D-printing prototyping approach and verification of the working principle for printed MEMS magnetometers.

Download Full-text

An Initial Effort to Create a Superficial Femoral Artery Ultrasound Phantom Using 3-Dimensional Printing

Journal for Vascular Ultrasound ◽

10.1177/1544316720911490 ◽

2020 ◽

Vol 44 (2) ◽

pp. 69-73

Author(s):

Paul D. Bishop ◽

Thomas Fultz ◽

Lisa Smith ◽

Ryan S. Klatte ◽

Francis Loth ◽

...

Keyword(s):

3D Printing ◽

Femoral Artery ◽

Superficial Femoral Artery ◽

Low Cost ◽

Duplex Ultrasound ◽

3D Print ◽

Stl File ◽

Calcified Plaque ◽

3D Printed ◽

Artery Geometry

Three-dimensional (3D) printing of anatomical structures has yielded valuable models for simulation, education, and surgical planning applications. Applications for 3D printing have continued to expand to include some ultrasound applications. The goal of this effort was to evaluate if a 3D printed model of a superficial femoral artery (SFA) would have realistic ultrasound characteristics. A computed tomography scan was 3D reconstructed and segmented using TeraRecon Aquarius Intuition software (TeraRecon, Foster City, California) to obtain an atherosclerotic SFA geometry. Both the lumen geometry and calcified plaque geometry of the SFA were exported as a stereolithographic (STL) file. The STL file was printed with An Object350 Connex 3D System using 2 different materials selected based on published elastic modulus data. VeroWhite was selected for the calcified plaque and TangoPlus Clear was selected for the artery wall. After printing, the SFA model was imaged in a water bath with a Phillips IU22 duplex ultrasound console and L12-9 ultrasound probe. Ultrasound imaging of the SFA model yielded grayscale views of artery geometry. Lumen geometry of the SFA model was similar to the actual artery geometry. Ultrasound was able to discern between the 3D print materials and visualize regions with stenosis. Suboptimal ultrasound parameters of echogenicity and wave velocity noted to differ from biological tissue. Total 3D print material cost was estimated at below $20. Although the 3D printed model did not have fully accurate ultrasound characteristics, it still provided realistic imaging. With further research, 3D printed models may offer a low-cost alternative for ultrasound phantoms.

Download Full-text

Development of Soft sEMG Sensing Structures Using 3D-Printing Technologies

Sensors ◽

10.3390/s20154292 ◽

2020 ◽

Vol 20 (15) ◽

pp. 4292

Author(s):

Gerjan Wolterink ◽

Pedro Dias ◽

Remco G. P. Sanders ◽

Frodo Muijzer ◽

Bert-Jan van Beijnum ◽

...

Keyword(s):

3D Printing ◽

Biceps Brachii ◽

Low Cost ◽

Recognition Algorithm ◽

Practical Applications ◽

Variable Level ◽

Processing Step ◽

Significant Difference ◽

3D Printed ◽

Emg Electrodes

3D printing of soft EMG sensing structures enables the creation of personalized sensing structures that can be potentially integrated in prosthetic, assistive and other devices. We developed and characterized flexible carbon-black doped TPU-based sEMG sensing structures. The structures are directly 3D-printed without the need for an additional post-processing step using a low-cost, consumer grade multi-material FDM printer. A comparison between the gold standard Ag/AgCl gel electrodes and the 3D-printed EMG electrodes with a comparable contact area shows that there is no significant difference in the EMG signals’ amplitude. The sensors are capable of distinguishing a variable level of muscle activity of the biceps brachii. Furthermore, as a proof of principle, sEMG data of a 3D-printed 8-electrode band are analyzed using a patten recognition algorithm to recognize hand gestures. This work shows that 3D-printed sEMG electrodes have great potential in practical applications.

Download Full-text

Evaluation of a Desktop 3D Printed Rigid Refractive-Indexed-Matched Flow Phantom for PIV Measurements on Cerebral Aneurysms

Cardiovascular Engineering and Technology ◽

10.1007/s13239-019-00444-z ◽

2019 ◽

Vol 11 (1) ◽

pp. 14-23 ◽

Cited By ~ 1

Author(s):

W. H. Ho ◽

I. J. Tshimanga ◽

M. N. Ngoepe ◽

M. C. Jermy ◽

P. H. Geoghegan

Keyword(s):

3D Printing ◽

Flow Visualization ◽

Investment Casting ◽

Flow Model ◽

Low Cost ◽

Ammonium Thiocyanate ◽

Cerebral Aneurysms ◽

Model Material ◽

Flow Phantom ◽

3D Printed

Abstract Purpose Fabrication of a suitable flow model or phantom is critical to the study of biomedical fluid dynamics using optical flow visualization and measurement methods. The main difficulties arise from the optical properties of the model material, accuracy of the geometry and ease of fabrication. Methods Conventionally an investment casting method has been used, but recently advancements in additive manufacturing techniques such as 3D printing have allowed the flow model to be printed directly with minimal post-processing steps. This study presents results of an investigation into the feasibility of fabrication of such models suitable for particle image velocimetry (PIV) using a common 3D printing Stereolithography process and photopolymer resin. Results An idealised geometry of a cerebral aneurysm was printed to demonstrate its applicability for PIV experimentation. The material was shown to have a refractive index of 1.51, which can be refractive matched with a mixture of de-ionised water with ammonium thiocyanate (NH4SCN). The images were of a quality that after applying common PIV pre-processing techniques and a PIV cross-correlation algorithm, the results produced were consistent within the aneurysm when compared to previous studies. Conclusions This study presents an alternative low-cost option for 3D printing of a flow phantom suitable for flow visualization simulations. The use of 3D printed flow phantoms reduces the complexity, time and effort required compared to conventional investment casting methods by removing the necessity of a multi-part process required with investment casting techniques.

Download Full-text

Low cost digital fabrication approach for thumb orthoses

Rapid Prototyping Journal ◽

10.1108/rpj-12-2015-0187 ◽

2017 ◽

Vol 23 (6) ◽

pp. 1020-1031 ◽

Cited By ~ 4

Author(s):

Miguel Fernandez-Vicente ◽

Ana Escario Chust ◽

Andres Conejero

Keyword(s):

3D Printing ◽

Computer Aided Design ◽

Low Cost ◽

Three Dimensional ◽

Recovery Process ◽

Digital Fabrication ◽

Cost Comparison ◽

Content Type ◽

Custom Made ◽

The Impact

Purpose The purpose of this paper is to describe a novel design workflow for the digital fabrication of custom-made orthoses (CMIO). It is intended to provide an easier process for clinical practitioners and orthotic technicians alike. It further functions to reduce the dependency of the operators’ abilities and skills. Design/methodology/approach The technical assessment covers low-cost three-dimensional (3D) scanning, free computer-aided design (CAD) software, and desktop 3D printing and acetone vapour finishing. To analyse its viability, a cost comparison was carried out between the proposed workflow and the traditional CMIO manufacture method. Findings The results show that the proposed workflow is a technically feasible and cost-effective solution to improve upon the traditional process of design and manufacture of custom-made static trapeziometacarpal (TMC) orthoses. Further studies are needed for ensuring a clinically feasible approach and for estimating the efficacy of the method for the recovery process in patients. Social implications The feasibility of the process increases the impact of the study, as the great accessibility to this type of 3D printers makes the digital fabrication method easier to be adopted by operators. Originality/value Although some research has been conducted on digital fabrication of CMIO, few studies have investigated the use of desktop 3D printing in any systematic way. This study provides a first step in the exploration of a new design workflow using low-cost digital fabrication tools combined with non-manual finishing.

Download Full-text