Review of Materials and Fabrication Methods for Flexible Nano and Micro-Scale Physical Property Sensors

The use of flexible sensors has tripled over the last decade due to the increased demand in various fields including health monitoring, food packaging, electronic skins and soft robotics. Flexible sensors have the ability to be bent and stretched during use and can still maintain their electrical and mechanical properties. This gives them an advantage over rigid sensors that lose their sensitivity when subject to bending. Advancements in 3D printing have enabled the development of tailored flexible sensors. Various additive manufacturing methods are being used to develop these sensors including inkjet printing, aerosol jet printing, fused deposition modelling, direct ink writing, selective laser melting and others. Hydrogels have gained much attention in the literature due to their self-healing and shape transforming. Self-healing enables the sensor to recover from damages such as cracks and cuts incurred during use and this enables the sensor to have a longer operating life and stability. Various polymers are used as substrates on which the sensing conductive material is placed. Polymers including polydimethylsiloxane (PDMS), polyvinyl acetate (PVA), and Kapton are extensively used in flexible sensors. The most widely used nanomaterials in flexible sensors are carbon and silver, however, other nanomaterials such as iron, copper, manganese dioxide and gold are also used to provide controlled levels of conductivity or other functional properties.

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Review of Materials and Fabrication Methods for Flexible Nano and Micro-Scale Physical and Chemical Property Sensors

Applied Sciences ◽

10.3390/app11188563 ◽

2021 ◽

Vol 11 (18) ◽

pp. 8563

Author(s):

Anesu Nyabadza ◽

Mercedes Vázquez ◽

Shirley Coyle ◽

Brian Fitzpatrick ◽

Dermot Brabazon

Keyword(s):

3D Printing ◽

Food Packaging ◽

Fused Deposition Modelling ◽

Self Healing ◽

Operating Life ◽

Flexible Sensors ◽

Fused Deposition ◽

Sensing Material ◽

Physical And Chemical ◽

Aerosol Jet Printing

The use of flexible sensors has tripled over the last decade due to the increased demand in various fields including health monitoring, food packaging, electronic skins and soft robotics. Flexible sensors have the ability to be bent and stretched during use and can still maintain their electrical and mechanical properties. This gives them an advantage over rigid sensors that lose their sensitivity when subject to bending. Advancements in 3D printing have enabled the development of tailored flexible sensors. Various additive manufacturing methods are being used to develop these sensors including inkjet printing, aerosol jet printing, fused deposition modelling, direct ink writing, selective laser melting and others. Hydrogels have gained much attention in the literature due to their self-healing and shape transforming. Self-healing enables the sensor to recover from damages such as cracks and cuts incurred during use, and this enables the sensor to have a longer operating life and stability. Various polymers are used as substrates on which the sensing material is placed. Polymers including polydimethylsiloxane, Poly(N-isopropylacrylamide) and polyvinyl acetate are extensively used in flexible sensors. The most widely used nanomaterials in flexible sensors are carbon and silver due to their excellent electrical properties. This review gives an overview of various types of flexible sensors (including temperature, pressure and chemical sensors), paying particular attention to the application areas and the corresponding characteristics/properties of interest required for such. Current advances/trends in the field including 3D printing, novel nanomaterials and responsive polymers, and self-healable sensors and wearables will also be discussed in more detail.

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Photonic curing of silver paths on 3D printed polymer substrate

Circuit World ◽

10.1108/cw-11-2018-0084 ◽

2019 ◽

Vol 45 (1) ◽

pp. 9-14

Author(s):

Jakub Krzeminski ◽

Bartosz Blicharz ◽

Andrzej Skalski ◽

Grzegorz Wroblewski ◽

Małgorzata Jakubowska ◽

...

Keyword(s):

Polymer Substrate ◽

Fused Deposition Modelling ◽

Content Type ◽

Fused Deposition ◽

Photonic Curing ◽

Structural Electronics ◽

Jet Printing ◽

3D Printed ◽

Aerosol Jet Printing ◽

Photonic Sintering

Purpose Despite almost limitless possibilities of rapid prototyping, the idea of 3D printed fully functional electronic device still has not been fulfilled – the missing point is a highly conductive material suitable for this technique. The purpose of this paper is to present the usage of the photonic curing process for sintering highly conductive paths printed on the polymer substrate. Design/methodology/approach This paper evaluates two photonic curing processes for the conductive network formulation during the additive manufacturing process. Along with the xenon flash sintering for aerosol jet-printed paths, this paper examines rapid infrared sintering for thick-film and direct write techniques. Findings This paper proves that the combination of fused deposition modeling, aerosol jet printing or paste deposition, along with photonic sintering, is suitable to obtain elements with low resistivity of 3,75·10−8 Ωm. Presented outcomes suggest the solution for fabrication of the structural electronics systems for daily-use applications. Originality/value The combination of fused deposition modelling (FDM) and aerosol jet printing or paste deposition used with photonic sintering process can fill the missing point for highly conductive materials for structural electronics.

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3D Printing of Solvent-Free Supramolecular Polymers

Frontiers in Chemistry ◽

10.3389/fchem.2021.771974 ◽

2021 ◽

Vol 9 ◽

Author(s):

Harald Rupp ◽

Wolfgang H. Binder

Keyword(s):

3D Printing ◽

Dynamic Properties ◽

Polymeric Materials ◽

Fundamental Principle ◽

Supramolecular Polymers ◽

Fused Deposition Modelling ◽

Self Healing ◽

Polymer Science ◽

Fused Deposition ◽

Molecular Ordering

Additive manufacturing has significantly changed polymer science and technology by engineering complex material shapes and compositions. With the advent of dynamic properties in polymeric materials as a fundamental principle to achieve, e.g., self-healing properties, the use of supramolecular chemistry as a tool for molecular ordering has become important. By adjusting molecular nanoscopic (supramolecular) bonds in polymers, rheological properties, immanent for 3D printing, can be adjusted, resulting in shape persistence and improved printing. We here review recent progress in the 3D printing of supramolecular polymers, with a focus on fused deposition modelling (FDM) to overcome some of its limitations still being present up to date and open perspectives for their application.

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Generating Porous Ceramic Scaffolds: Processing and Properties

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.441.155 ◽

2010 ◽

Vol 441 ◽

pp. 155-179 ◽

Cited By ~ 12

Author(s):

Ulrike Deisinger

Keyword(s):

Rapid Prototyping ◽

Porous Ceramic ◽

Selective Laser Sintering ◽

Three Dimensional ◽

Pore Geometry ◽

Fused Deposition Modelling ◽

Fused Deposition ◽

New Methods ◽

Ink Jet ◽

Jet Printing

For tissue regeneration in medicine three-dimensional scaffolds with specific characteristics are required. A very important property is a high, interconnecting porosity to enable tissue ingrowth into the scaffold. Pore size distribution and pore geometry should be adapted to the respective tissue. Additionally, the scaffolds should have a basic stability for handling during implantation, which is provided by ceramic scaffolds. Various methods to produce such ceramic 3D scaffolds exist. In this paper conventional and new fabrication techniques are reviewed. Conventional methods cover the replica of synthetic and natural templates, the use of sacrificial templates and direct foaming. Rapid prototyping techniques are the new methods listed in this work. They include fused deposition modelling, robocasting and dispense-plotting, ink jet printing, stereolithography, 3D-printing, selective laser sintering/melting and a negative mould technique also involving rapid prototyping. The various fabrication methods are described and the characteristics of the resulting scaffolds are pointed out. Finally, the techniques are compared to find out their disadvantages and advantages.

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3D Printing of a Self-Healing Thermoplastic Polyurethane through FDM: From Polymer Slab to Mechanical Assessment

Polymers ◽

10.3390/polym13020305 ◽

2021 ◽

Vol 13 (2) ◽

pp. 305

Author(s):

Linda Ritzen ◽

Vincenzo Montano ◽

Santiago J. Garcia

Keyword(s):

3D Printing ◽

Room Temperature ◽

Thermoplastic Polyurethane ◽

The Self ◽

Added Value ◽

Fused Deposition Modelling ◽

Full Potential ◽

Self Healing ◽

Fused Deposition ◽

3D Printed

The use of self-healing (SH) polymers to make 3D-printed polymeric parts offers the potential to increase the quality of 3D-printed parts and to increase their durability and damage tolerance due to their (on-demand) dynamic nature. Nevertheless, 3D-printing of such dynamic polymers is not a straightforward process due to their polymer architecture and rheological complexity and the limited quantities produced at lab-scale. This limits the exploration of the full potential of self-healing polymers. In this paper, we present the complete process for fused deposition modelling of a room temperature self-healing polyurethane. Starting from the synthesis and polymer slab manufacturing, we processed the polymer into a continuous filament and 3D printed parts. For the characterization of the 3D printed parts, we used a compression cut test, which proved useful when limited amount of material is available. The test was able to quasi-quantitatively assess both bulk and 3D printed samples and their self-healing behavior. The mechanical and healing behavior of the 3D printed self-healing polyurethane was highly similar to that of the bulk SH polymer. This indicates that the self-healing property of the polymer was retained even after multiple processing steps and printing. Compared to a commercial 3D-printing thermoplastic polyurethane, the self-healing polymer displayed a smaller mechanical dependency on the printing conditions with the added value of healing cuts at room temperature.

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A Post-Treatment Method to Enhance the Property of Aerosol Jet Printed Electric Circuit on 3D Printed Substrate

Materials ◽

10.3390/ma13245602 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5602

Author(s):

Bing Wang ◽

Haining Zhang ◽

Joon Phil Choi ◽

Seung Ki Moon ◽

Byunghoon Lee ◽

...

Keyword(s):

Electrical Resistance ◽

High Performance ◽

Electronic Devices ◽

Electric Circuit ◽

Treatment Method ◽

Post Treatment ◽

Original Structure ◽

Fused Deposition ◽

Jet Printing ◽

Aerosol Jet Printing

Aerosol jet printing of electronic devices is increasingly attracting interest in recent years. However, low capability and high resistance are still limitations of the printed electronic devices. In this paper, we introduce a novel post-treatment method to achieve a high-performance electric circuit. The electric circuit was printed with aerosol jet printing method on an ULTEM substrate. The ULTEM substrate was fabricated by the Fused Deposition Modelling method. After post-treatment, the electrical resistance of the printed electric circuit was changed from 236 mΩ to 47 mΩ and the electric property was enhanced. It was found that the reduction of electric resistance was caused by surface property changes. Different surface analysis methods including scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) were used to understand the effectiveness of the proposed method. The results showed that the microsurface structure remained the same original structure before and after treatment. It was found that the surface carbon concentration was significantly increased after treatment. Detailed analysis showed that the C-C bond increased obviously after treatment. The change of electrical resistance was found to be limited to the material’s surface. After polishing, the circuit resistance was changed back to its original value. As the electric circuit is the basic element of electric devices, the proposed method enables the fabrication of high performance devices such as capacitors, strain gauge, and other sensors, which has potential applications in many areas such as industrial, aerospace, and military usage.

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A Flexible Ultrasensitive IgG-Modified rGO-Based FET Biosensor Fabricated by Aerosol Jet Printing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.748.157 ◽

2015 ◽

Vol 748 ◽

pp. 157-161 ◽

Cited By ~ 1

Author(s):

Wei Yu ◽

Pei Jie Cai ◽

Rui Liu ◽

Fang Ping Shen ◽

Ting Zhang

Keyword(s):

High Performance ◽

Low Cost ◽

Drain Current ◽

Flexible Sensors ◽

Flexible Polymer ◽

Low Concentrations ◽

Rabbit Igg ◽

Jet Printing ◽

Aerosol Jet Printing ◽

Flexible Polymer Substrate

High-performance biosensors are the key elements for rapid and real-time detection of specific biomolecules. Herein, an ultrasensitive FET biosensor on a flexible polymer substrate was reported, and the aerosol jet printing (AJP) method offers a unique way for low-cost mass manufacturing of the flexible sensors. The stable PBA functionalized rGO layer and the goat-anti-rabbit IgG layer on the rGO were both printed by AJP method between the source/drain electrodes. The flexibe biosensors exposure to low concentrations of target rabbit IgG showed dramatic increase in the source-drain current, which exhibited great sensing performance with the lowest detection limit of 13 fM.

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Evaluation of geometrical benchmark artifacts containing multiple overhang lengths fabricated using material extrusion technique

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.14.3.2020.28.0573 ◽

2020 ◽

Vol 14 (3) ◽

pp. 7296-7308

Author(s):

Siti Nur Humaira Mazlan ◽

Aini Zuhra Abdul Kadir ◽

N. H. A. Ngadiman ◽

M.R. Alkahari

Keyword(s):

3D Model ◽

Laser Scanner ◽

Dimensional Accuracy ◽

Fused Deposition Modelling ◽

Layer By Layer ◽

Fused Deposition ◽

Layer Technique ◽

Subtractive Manufacturing ◽

Manufacturing Features ◽

Layer Problem

Fused deposition modelling (FDM) is a process of joining materials based on material entrusion technique to produce objects from 3D model using layer-by-layer technique as opposed to subtractive manufacturing. However, many challenges arise in the FDM-printed part such as warping, first layer problem and elephant food that was led to an error in dimensional accuracy of the printed parts especially for the overhanging parts. Hence, in order to investigate the manufacturability of the FDM printed part, various geometrical and manufacturing features were developed using the benchmarking artifacts. Therefore, in this study, new benchmarking artifacts containing multiple overhang lengths were proposed. After the benchmarking artifacts were developed, each of the features were inspected using 3D laser scanner to measure the dimensional accuracy and tolerances. Based on 3D scanned parts, 80% of the fabricated parts were fabricated within ±0.5 mm of dimensional accuracy as compared with the CAD data. In addition, the multiple overhang lengths were also successfully fabricated with a very significant of filament sagging observed.

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