Ultrasound Transducer Array Fabrication Based on Additive Manufacturing of Piezocomposites

Conventional methods for fabricating ultrasound imaging transducer arrays, especially for high frequency range (>20 MHz), are expensive, time consuming and limited to relatively simple geometries. In this paper, the development of an additive manufacturing (AM) process based on digital micromirror devices (DMDs) is presented for the fabrication of piezoelectric devices such as ultrasound transducer arrays. Both green-part fabrication and the sintering of fabricated green-parts have been studied. A novel two-channel design in the bottom-up projection system is presented to address the piezo-composite fabrication challenges including a small curing depth and viscous ceramic slurry recoating. A prototype system has been developed for the fabrication of green-parts with complex shapes and small features. Based on the fabricated green-parts, the challenges in the sintering process for achieving desired functionality are discussed. Various approaches for increasing the density of sintered components are presented. Dielectric and piezoelectric properties of the fabricated samples are measured and compared with those of bulk PZT samples. Based on the identified challenges in the DMD-based AM process, future work for achieving fully functional piezoelectric ceramic components is discussed.

Download Full-text

Piezoelectric component fabrication using projection-based stereolithography of barium titanate ceramic suspensions

Rapid Prototyping Journal ◽

10.1108/rpj-11-2015-0162 ◽

2017 ◽

Vol 23 (1) ◽

pp. 44-53 ◽

Cited By ~ 27

Author(s):

Xuan Song ◽

Zeyu Chen ◽

Liwen Lei ◽

Kirk Shung ◽

Qifa Zhou ◽

...

Keyword(s):

Additive Manufacturing ◽

Manufacturing Process ◽

Ferroelectric Properties ◽

Tape Casting ◽

Prototype System ◽

Ultrasound Transducers ◽

Post Processing ◽

Projection System ◽

Content Type ◽

Ceramic Suspensions

Purpose Conventional machining methods for fabricating piezoelectric components such as ultrasound transducer arrays are time-consuming and limited to relatively simple geometries. The purpose of this paper is to develop an additive manufacturing process based on the projection-based stereolithography process for the fabrication of functional piezoelectric devices including ultrasound transducers. Design/methodology/approach To overcome the challenges in fabricating viscous and low-photosensitive piezocomposite slurry, the authors developed a projection-based stereolithography process by integrating slurry tape-casting and a sliding motion design. Both green-part fabrication and post-processing processes were studied. A prototype system based on the new manufacturing process was developed for the fabrication of green-parts with complex shapes and small features. The challenges in the sintering process to achieve desired functionality were also discussed. Findings The presented additive manufacturing process can achieve relatively dense piezoelectric components (approximately 95 per cent). The related property testing results, including X-ray diffraction, scanning electron microscope, dielectric and ferroelectric properties as well as pulse-echo testing, show that the fabricated piezo-components have good potentials to be used in ultrasound transducers and other sensors/actuators. Originality/value A novel bottom-up projection system integrated with tape casting is presented to address the challenges in the piezo-composite fabrication, including small curing depth and viscous ceramic slurry recoating. Compared with other additive manufacturing processes, this method can achieve a thin recoating layer (as small as 10 μm) of piezo-composite slurry and can fabricate green parts using slurries with significantly higher solid loadings. After post processing, the fabricated piezoelectric components become dense and functional.

Download Full-text

Production of complex shape magnets using additive manufacturing: A state-of-the-art analysis

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705719886894 ◽

2019 ◽

pp. 089270571988689

Author(s):

Thiago Felipe Vieira Silva ◽

Marcelo Henrique Stoppa

Keyword(s):

Additive Manufacturing ◽

Magnetic Particles ◽

Permanent Magnets ◽

State Of The Art ◽

Heating Temperature ◽

Maximum Energy ◽

Sintering Process ◽

Capacity Limits ◽

Main Compound ◽

Complex Shapes

Additive manufacturing has been gaining ground both in the industry and in the academic world due to its flexibility, easy operation, and the possibility of making products in the most varied formats. Also, it can be observed that magnets are largely produced using a sintering process, although it results in high (BH)max, this process is very limited in relation to the shapes of the magnets, thus, additive manufacturing can be used to produce complex shaped magnets. The aim of this article is to demonstrate the state of the art regarding the applied methods to produce permanent magnets and materials for magnet production. Considering this, a literature review was conducted using the methodology called mapping study to select the articles to be used, thus, demonstrating that the main compound used as the magnetic particle is NdFeB alloy powder. Finally, it can be concluded that the magnets produced by additive manufacturing have lower (BH)max than those produced by sintering processes, which despite having high filling capacity of magnetic particles increases the magnet’s magnetic capacity, limits their shape, those by manufacturing magnets can be produced with complex shapes, the heating temperature may reduce the maximum energy, and the coercive force improves it.

Download Full-text

Fabrication of Conformal Ultrasound Transducer Arrays and Horns Based on Multi-Axis CNC Accumulation

ASME 2011 International Manufacturing Science and Engineering Conference, Volume 1 ◽

10.1115/msec2011-50139 ◽

2011 ◽

Cited By ~ 1

Author(s):

Yayue Pan ◽

Chi Zhou ◽

Yong Chen ◽

Jouni P. Partanen

Keyword(s):

Tool Path ◽

Ultrasound Transducer ◽

Prototype System ◽

Test Cases ◽

Internal Organs ◽

Acoustic Performance ◽

Spherical Surfaces ◽

Transducer Arrays ◽

Planning Methods ◽

Potential Use

Ultrasonic imaging is an important medical imaging technique. It uses ultrasound over 20K Hz to detect and visualize muscles, tendons, and many internal organs. Previous studies have shown that an improved acoustic performance can be achieved by conformal ultrasound transducer arrays and horns that can wrap conformably around curved surfaces. To address challenges in fabricating such curved ultrasound transducer arrays and horns, we investigate the possibility of using a newly developed additive manufacturing (AM) process named CNC accumulation. In such an AM process, an accumulation tool can have multi-axis motion, which is beneficial for building conformal ultrasound transducer arrays and horns on a curved surface. To address different resolution requirements, we illustrate the use of multiple accumulation tools that can have different curing sizes and power in the fabrication of a single component. The tool path planning methods for any given cylindrical and spherical surfaces have been discussed. Based on the developed prototype system, various test cases have been performed. The experimental results have illustrated the capability of the process and its potential use in the fabrication of conformal ultrasound transducer arrays and horns. The current limitations and future development have also been discussed.

Download Full-text

Toward Metamodels for Composable and Reusable Additive Manufacturing Process Models

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4028533 ◽

2014 ◽

Vol 136 (6) ◽

Cited By ~ 28

Author(s):

Paul Witherell ◽

Shaw Feng ◽

Timothy W. Simpson ◽

David B. Saint John ◽

Pan Michaleris ◽

...

Keyword(s):

Additive Manufacturing ◽

Metal Powder ◽

Manufacturing Process ◽

Process Model ◽

Model Development ◽

Process Models ◽

Powder Bed Fusion ◽

Powder Bed ◽

Future Work ◽

Am Processes

In this paper, we advocate for a more harmonized approach to model development for additive manufacturing (AM) processes, through classification and metamodeling that will support AM process model composability, reusability, and integration. We review several types of AM process models and use the direct metal powder bed fusion AM process to provide illustrative examples of the proposed classification and metamodel approach. We describe how a coordinated approach can be used to extend modeling capabilities by promoting model composability. As part of future work, a framework is envisioned to realize a more coherent strategy for model development and deployment.

Download Full-text

Sustainability of additive manufacturing: measuring the energy consumption of the laser sintering process

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405411406044 ◽

2011 ◽

Vol 225 (12) ◽

pp. 2228-2239 ◽

Cited By ~ 79

Author(s):

M Baumers ◽

C Tuck ◽

D L Bourell ◽

R Sreenivasan ◽

R Hague

Keyword(s):

Energy Consumption ◽

Additive Manufacturing ◽

Laser Sintering ◽

Sintering Process

Download Full-text

Enhancing Creative Redesign through Multi-Modal Design Heuristics for Additive Manufacturing

Journal of Mechanical Design ◽

10.1115/1.4050656 ◽

2021 ◽

pp. 1-52

Author(s):

Alexandra Bloesch-Paidosh ◽

Kristina Shea

Keyword(s):

Additive Manufacturing ◽

Design Process ◽

User Studies ◽

Novice User ◽

Design Heuristics ◽

Industrial Setting ◽

Derived Design ◽

Mind Set ◽

Future Work ◽

Early Phases

Abstract When designing for Additive Manufacturing (AM), designers often need assistance in breaking out of their conventional manufacturing mind-set. Previously, Blösch-Paidosh and Shea (2019) derived Design Heuristics for AM (DHAM) to assist designers in doing this during the early phases of the design process. This work proposes a set of 25 multi-modal cards and objects to accompany each of the Design Heuristics for AM and studies their effect through a series of controlled, novice user studies conducted using both teams and individuals who redesign a city E-Bike. The resulting AM concepts are analyzed in terms of the quantity of design modifications relevant for AM, AM-flexibility, novelty, and variety. It is found that the DHAM cards and objects increase the inclusion of AM concepts, AM modifications, and the unique capabilities of AM in the concepts generated by both individuals and teams. They also increase the creativity of the concepts generated by both individuals and teams, as measured through a series of defined metrics. Further, the objects in combination with the cards are more effective at stimulating the generation of a wider variety of designs than the cards alone. Future work will focus on studying the use of the DHAM cards and objects in an industrial setting.

Download Full-text

Shape-driven control of layer height in robotic wire and arc additive manufacturing

Rapid Prototyping Journal ◽

10.1108/rpj-11-2018-0295 ◽

2019 ◽

Vol 25 (10) ◽

pp. 1637-1646 ◽

Cited By ~ 1

Author(s):

Bohao Xu ◽

Xiaodong Tan ◽

Xizhi Gu ◽

Donghong Ding ◽

Yuelin Deng ◽

...

Keyword(s):

Additive Manufacturing ◽

Deposition Rate ◽

Control Method ◽

Single Layer ◽

Optimization Method ◽

Content Type ◽

Layer Height ◽

Layer Deposition ◽

Complex Shapes ◽

The Difference

Purpose Once an uneven substrate is aligned, traditional control theories and methods can be used on it, so aligning is of great significance for the development of wire and arc additive manufacturing (WAAM). This paper aims to propose a shape-driven control method for aligning a substrate with slopes to expand the application of WAAM. Design/methodology/approach A substrate with slopes must be aligned by depositing weld beads with slopes. First, considering the large height differences of slopes, multi-layer deposition is needed, and the number of layer of weld beads must be ascertained. Second, the change in the deposition rate is controlled as a ramp function to generate weld beads with slopes. Third, the variation of the deposition rate must be fine-tuned to compensate for the deviation between the actual and theoretical layer heights at the deposition of each layer. Finally, the parameters of the ramp functions at the deposition of each layer are determined through an optimization method. Findings First, to model the response function of layer height to deposition rate, the experiments are conducted with the deposition rate jumping from 4 to 8 mm/s and from 8 to 4 mm/s. When the deposition rate jumps from 4 to 8 mm/s and from 8 to 4 mm/s, the difference in the height of each layer decreases as the number of layer increases. Second, the variation of the deposition rate can be fine-tuned based on the deviation between the measured and theoretical layer heights because the variation of the deposition rate is proportional to the layer height when the initial and end deposition rates are near 4 or 8 mm/s, respectively. Third, the experimental results demonstrate that the proposed method is effective for single-layer aligning and aligning a substrate with one or more slopes. Originality/value The proposed method can expand the application of WAAM to an uneven substrate with slopes and lays the foundation for aligning tasks focused on uneven substrates with more complex shapes.

Download Full-text