Name: production of a strain-measuring device with an improved 3d printer
Uploaded: 2020-01-30T14:30:00
Description: Watch this Scientific Journal Video about Production of a Strain-Measuring Device with an Improved 3D Printer at JoVE.com

This work was financially supported by the National Science Foundation of China (Grant No. 51805009).

1. Assembly of the amplification mechanism
<ol>
	<li>Construct an experimental platform including an improved 3D printer, a strain gauge indicator, a driving device, a support frame, an aluminum bar, a PDMS lens, a smartphone, weights, a printed amplifier (Supplemental Figure 1), and a strain gauge, as shown in Figure 1.</li>
	<li>Set the height of each layer in the printer at 0.05 mm for nylon and 0.2 mm for ABS. Set the diameter of the printing head to 0.2 mm in both cas...

<ol>
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The output displacement evolved linearly with the force concentrated at the free end of the cantilever beam and was consistent with the FEA simulations. The sensitivity of the amplifiers was 36.55 &#177; 0.53 &#956;&#949;/&#956;m for nylon and 36.03 &#177; 1.34 &#956;&#949;/&#956;m for ABS. The stable sensitivity confirmed the feasibility and the effectiveness of the rapid prototyping of high-precision sensors using 3D printing. The amplifiers had a high sensitivity and were free of electromagnetic interference. In addit...

Obtaining light but strong materials is particularly important in modern industry. The properties of materials are affected when subjected to stress, pressure, torsion, and bending vibration during use1,2. Thus, strain measurement of materials is important to analyze their durability and troubleshoot usage. Such measurements enable engineers to analyze the durability of materials and troubleshoot production problems. The most common strain measurement method in industry uses strain sensors3. Traditional foil sensors are widely used because of their low cost and good reliability4. They measure the changes in electrical signals and convert them to different output signals5,6. However, this method leaves out the details of the strain profile in the measured object and is susceptible to noise from vibrational electromagnetic interference with analog signals. Developing accurate, highly repeatable, and easy material strain measurement methods is important in engineering. Thus, other methods are being studied.
In recent years, nanomaterials have drawn much interest from investigators. To measure strain on small objects, Osborn et al.7,8 proposed a method to measure the strain of 3D nanomaterials using electron backscatter (EBSD). Using molecular dynamics, Lina et al.9 investigated the interlayer friction strain engineering of graphene. Distributed optical fiber strain measurements using Rayleigh backscatter spectroscopy (RBS) have been widely used in fault detection and for the evaluation of optical devices due to their high spatial resolution and sensitivity10. Grating fiber optic (FBG)11,12 distributed strain sensors have been widely used for high-precision strain measurement13 for their sensitivity to temperature and strain. In order to monitor the strain changes caused by curing after resin injection, Sanchez et al.14 embedded a fiberoptic sensor into an epoxy carbon fiber plate and measured the complete strain process. Differential interference contrast (DIC) is a powerful measurement method of the field deformation15,16,17 that is widely used as well18. By comparing the changes of measured surface gray levels in the collected images, the deformation is analyzed, and the strain calculated. Zhang et al.19 proposed a method that relies on the introduction of reinforced particles and DIC images to evolve from traditional DIC. Vogel and Lee20 calculated strain values using an automatic two-view method. In recent years, this enabled simultaneous microstructure observation and strain measurement in particle-reinforced composites. Traditional strain sensors only effectively measure strain in one direction. Zymelka et al.21 proposed an omnidirectional flexible strain sensor that improves a traditional strain gauge method by detecting changes in the sensor resistance. It is also possible to measure strain using biological or chemical substances. For instance, ionic conductive hydrogels are an effective alternative to strain/tactile sensors due to their good tensile properties and high sensitivity22,23. Graphene and its composites have excellent mechanical properties and provide a high carrier mobility along with good piezoresistivity24,25,26. Consequently, graphene-based strain sensors have been widely used in electronic skin health monitoring, wearable electronics, and other fields27,28.
In this work, a conceptual strain measurement using a polydimethylsiloxane (PDMS) microscope and an amplification system is presented. The device is different from a traditional strain gauge because it does not require wires or electrical connections. Moreover, displacement can be observed directly. The amplification mechanism can be placed at any location on the tested object, which greatly increases the repeatability of the measurements. In this study, a sensor and a strain amplifier were made by 3D printing technology. We first improved the 3D printer to increase its efficiency for our requirements. A spherical extrusion device was designed to replace the traditional single-material extruder controlled by the slicing software to complete the conversion of the metal and plastic nozzles. The corresponding molding platform was changed, and the displacement-sensing device (amplifier) and the reading device (PDMS microscope) were integrated.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>ABS</td>
			<td>Hengli dejian plastic electrical products factory</td>
			<td></td>
			<td>Used for printing 1.75 mm diameter wire for amplifying mechanism</td>
		</tr>
		<tr>
			<td>Aluminum 6063 T83 bar</td>
			<td></td>
			<td></td>
			<td>The length, width and thickness of cantilever beam are 380 mm, 51 mm, and 3.8 mm.</td>
		</tr>
		<tr>
			<td>ANSYS</td>
			<td>ANSYS</td>
			<td>ANSYS 14.5</td>
			<td></td>
		</tr>
		<tr>
			<td>CURA</td>
			<td>Ultimaker</td>
			<td>Cura 3.0</td>
			<td>Slicing softare,using with the improved 3D printer</td>
		</tr>
		<tr>
			<td>Curing agent</td>
			<td>Dow Corning</td>
			<td></td>
			<td>PDMS and curing agent are mixed with the weight ratio of 10:1</td>
		</tr>
		<tr>
			<td>Driving device</td>
			<td>Xinmingtian</td>
			<td>E00</td>
			<td></td>
		</tr>
		<tr>
			<td>Improved 3D printer and accessories</td>
			<td></td>
			<td></td>
			<td>Made by myself. The rotary spherical lifting platform is adopted. The spherical lifting platform is equipped with a nozzle and a pipette, which can be switched and printed freely. With a rotary printing platform, the platform temperature can be freely controlled.</td>
		</tr>
		<tr>
			<td>iPhone 6</td>
			<td>Apple</td>
			<td>MG4A2CH/A</td>
			<td>8-megapixel sensor and the equivalent focus distance is 29mm</td>
		</tr>
		<tr>
			<td>Magenetic stirrer</td>
			<td>SCILOGEX</td>
			<td>MS-H280-Pro</td>
			<td></td>
		</tr>
		<tr>
			<td>Nylon</td>
			<td>Hengli dejian plastic electrical products factory</td>
			<td></td>
			<td>Used for printing 1.75 mm diameter wire for amplifying mechanism</td>
		</tr>
		<tr>
			<td>PDMS</td>
			<td>Dow Corning</td>
			<td>SYLGARDDC184</td>
			<td>After the viscous mixture is heated and hardened, it can be combined with the lens amplification device of the mobile phone for image acquisition.</td>
		</tr>
		<tr>
			<td>Shape analyzer</td>
			<td>Gltech</td>
			<td>SURFIEW 4000</td>
			<td></td>
		</tr>
		<tr>
			<td>Solidworks</td>
			<td>Dassault Systems</td>
			<td>Solidworks 2017</td>
			<td>Assist to modelling</td>
		</tr>
		<tr>
			<td>VISHAY strain gauge</td>
			<td>Vishay</td>
			<td></td>
			<td>Used to measure the strain produced in the experiment.</td>
		</tr>
		<tr>
			<td>VISHAY strain gauge indicator</td>
			<td>Vishay</td>
			<td></td>
			<td>Strain data acquisition.</td>
		</tr>
	</tbody>
</table>

production of a strain-measuring device with an improved 3d printer

A traditional strain measurement sensor needs to be electrified and is susceptible to electromagnetic interference. In order to solve the fluctuations in the analog electrical signal in a traditional strain gauge operation, a new strain measurement method is presented here. It uses a photographic technique to display the strain change by amplifying the change of the pointer displacement of the mechanism. A visual polydimethylsiloxane (PDMS) lens with a focal length of 7.16 mm was added to a smartphone camera to generate a lens group acting as a microscope to capture images. It had an equivalent focal length of 5.74 mm. Acrylonitrile butadiene styrene (ABS) and nylon amplifiers were used to test the influence of different materials on the sensor performance. The production of the amplifiers and PDMS lens is based on improved 3D printing technology. The data obtained were compared with the results from finite element analysis (FEA) to verify their validity. The sensitivity of the ABS amplifier was 36.03 &plusmn; 1.34 &#181;&epsilon;/&#181;m, and the sensitivity of the nylon amplifier was 36.55 &plusmn; 0.53 &#181;&epsilon;/&#181;m.

When the platform temperature increased, the droplet diameter and the curvature radius decreased, whereas the contact angle increased (Figure 3). Therefore, the focal length of the PDMS increased. However, for platform temperatures above 220 &#176;C, a very short curing time was observed in the droplets, and they could not extend into a plane-convex shape. This can be attributed to the low attachment area when adhering onto a smartphone camera. Therefore, only soft lenses formed at 220 &#176...

Watch this Scientific Journal Video about Production of a Strain-Measuring Device with an Improved 3D Printer at JoVE.com

Production of a Strain-Measuring Device with an Improved 3D Printer

This work presents a strain measurement sensor consisting of an amplification mechanism and a polydimethylsiloxane microscope manufactured using an improved 3D printer.

A traditional strain measurement sensor needs to be electrified and is susceptible to electromagnetic interference. In order to solve the fluctuations in ...

The two-phase solid-liquid fabrication can also be applied to the manufacturing of structural microsphere materials in various field of study, including the electronics, biopharmaceutical, energy, and defense sectors. This system does not require wires or electrical connection and allows a wide range of applications related to microstructure deformation to be measured. Before beginning the procedure, construct an experimental platform that includes a modified 3-D printer, a strain gauge indicator, a driving device, a support frame, an aluminum bar, a PDMS lens, a smartphone, weights, a printed amplifier, and a strain gauge.Set the height of the nylon layer in the printer to 0.05 millimeters. Set the diameter of the printing head to 0.2 millimeters, and set the nozzle temperature to 220 degrees Celsius. Set the printing speed to 2000 millimeters per minute.Adjust the orientation of the spherical extrusion head so that the metal nozzle faces the low temperature platform and print a contour to ensure a normal extrusion. Then hang the nylon on the column. The front end must enter the printing coil container to be melted by the metal nozzle.To assemble the PDMS microscope, use a magnetic stirrer to mix a 10 to one weight ratio of PDMS precursor to curing agent solution and de-gas the mixture for 40 minutes. When all of the bubbles have been removed, pour the mixture into the PDMS container of the spherical extrusion head and rotate the spherical extrusion head and platform so that the plastic nozzle faces the high temperature platform. Set the plastic nozzle increment to 50 microliters and use the nozzle rotation and the stepper motor in the Z-axis to place the bottom end of the pipette device 20 millimeters away from the mold.Then heat the high temperature platform and squeeze the PDMS container to print the PDMS lens. When the printed PDMS lens has cooled to room temperature, use rubber tweezers to remove it from the printer. To perform a loading test strain measurement, use nuts and bolts to fix one end of a 380 by 51 by 3.8 millimeter aluminum 6063-T83 bar to the operating table and draw a cross at the center and 160 millimeters from the free end of the cantilever beam.To remove the oxide layer on the beam, polish the surface with fine sandpaper at an about 45 degree angle from the direction of the strain gauge wire grid. Use cotton wool soaked in acetone to wipe the surface of the sanded cantilever beam and the surface of the strain gauge paste. Then connect the driving device and the strain gauge indicator and turn on the power.Next, mount a strain gauge onto the center surface of the aluminum bar at its fixed end and fix a standard weight to the free end of the cantilever beam to control the concentrated force input. Record a baseline read-out using a conventional strain gauge indicator with a quarter bridge connection method before replacing the strain gauge with a nylon amplifier. Attach the PDMS lens onto a smartphone camera with an eight megapixel sensor at a focus distance of 29 millimeters and adjust the focal length of the camera until a clear image is obtained.Then use the PDMS microscope to read the displacement of the pointer. To perform a finite element analysis, import the cantilever beam and the amplifying mechanism into the material library of the software and simulate their placement positions. Analyze the mechanical properties of the amplifying mechanism pointer under the action of a cantilever beam and use tetrahedral elements with a fine element size to generate meshes for use in 3-D geometric models.Then refine the flexure hinges, especially the hinge between the pointer and the other bodies, and apply a concentrated force of one newton to the center of the free end of the cantilever beam. As the platform temperature is increased, the droplet diameter and curvature radius decrease, and the contact angle increases. Here a comparison of the experimental displacement measurement with the FEA simulations for nylon is shown, while this graph illustrates the minimum and maximum discrepancies between the slopes for ABS.In this representative experiment, the measurement sensitivities for nylon and ABS were determined. Controlling the molding temperature of the PDMS lens is difficult. We use a non-contact infrared radiation thermometer and high-temperature platform to ensure that the temperature changes are within tolerance.This solid-liquid manufacturing method can also be applied to studies in the biopharmaceuticals field, particularly for the preparation of microsphere structures.

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The purpose of this paper is to present the method of a soft tooling process chain employing Additive Manufacturing (AM) for fabrication of injection ...

A Standard and Reliable Method to Fabricate Two-Dimensional Nanoelectronics

Two-dimensional (2D) materials have attracted huge attention due to their unique properties and potential applications. Since wafer scale synthesis of 2D ...

A Polymer-based Piezoelectric Vibration Energy Harvester with a 3D Meshed-Core Structure

In this study, we fabricated a flexible 3D mesh structure with periodic voids by using a 3D lithography method and applying it to a vibration energy ...

3D Printing - Evaluating Particle Emissions of a 3D Printing Pen

Three-dimensional (3D) printing as a type of additive manufacturing shows continuing increase in application and consumer popularity. The fused filament ...

Elaborate Control of Inkjet Printer for Fabrication of Chip-based Supercapacitors

There are tremendous efforts in various fields to apply the inkjet printing method for the fabrication of wearable devices, displays, and energy storage ...