Page 23 - MSAM-3-2

Materials Science in Additive Manufacturing Functional materials for AM

Table 7. Comparison of materials and fabrication methods for carbon‑based materials
Printing method Composition Application Performance References
Inkjet Poly (3,4ethylenedioxythiophene), Chemical sensor Sensitivity (ΔS/ΔC) of 24.4×10 and short 135
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COOH, PEDOT: PSS, CNT response/recovery times of 13/60 at 1000 ppm
Screen Graphene-carbon ink Humidity sensor resistance-humidity gradient was~12.4 Ω/%RH 136
(room humidity) on 25%RH to 91.7%RH
Extrusion Pristine graphene formulated from VOC sensor Detect chemical substances - ethanol, methanol, 142
ethyl cellulose, toluene/ethanol and acetone within the range of 5 to 100 ppm.
Laser-induced forward SWCNTs/SnO2 NPs Chemical sensor At room temperature, NH response time of 13 s 144
3
transfer (NH ) for 25 ppm
3
Meniscus MWNTs, PVP Strain sensor Gauge factors of 12.87 at compressive strain and 137
13.07 at tensile strain at over 1500 bending cycles
FDM Graphene-based polylactic acid, TPU Strain sensor High level of sensitivity 138
Inkjet Graphene nano-sheets, green Battery ~942 mAh/g at 0.1 C. With the 100 cycles of 140
solvent: ethanol, stabilizer: 1 wt% bending, 87% capacity remained.
ethyl-cellulose
Inkjet LiFePO /AB/CNT Battery 150 mAh/g at 0.1 C with 150 cycles 141
4
Vat photopolymerization PEGDA, Sudan I, GPE, PC, EC, Battery Capacity of 1.4 μAh/cm after 2 cycles. 143
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(SLA) Carbon black
Abbreviations: AB: Acetylene Black; CNT: Carbon nanotube; EC: Ethylene Carbonate; FDM: Fused deposition modeling; GPE: Gel Polymer
Electrolyte; MWNTs: Multiwall nanotubes; NPs: Nanoparticles; PC: Propylene Carbonate; PEDOT: PSS: Poly (3,4-ethylenedioxythiophene) polystyrene
sulfonate; PVP: Polyvinylpyrrolidone; SLA: Stereolithography; SWCNTs: Single-walled carbon nanotube; TPU: Thermoplastic polyurethane;
VOC: Volatile organic compound.

sensors exhibit notable sensitivity to various compounds, it applicable in various fields. Furthermore, a volatile
with short response and recovery times. Similarly, strain organic compound sensor was developed using pristine
sensors can sensitively detect structural deformations and graphene formulated from ethyl cellulose and toluene/
stresses. Consequently, carbon-based chemical and strain ethanol through extrusion printing. Sized approximately
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sensors demonstrate innovative application potentials 12 μm, it demonstrated the capability to detect chemical
across various industries. substances such as ethanol, methanol, and acetone within
the range of 5 – 100 ppm. A formula relating concentration
(a) Chemical sensors
in ppm and resistance variation was derived, enabling
Chemical sensors rely on chemical reactions altering the current concentration measurements. The miniaturization
material’s properties, forming the fundamental principle of existing sensors suggests the potential to advance
of their operation. Due to the durability and outstanding portable chemical sensor technology, thereby leading to the
properties of carbon-based materials, they are often development of portable chemical sensors. Furthermore,
utilized in chemical sensors. For instance, a highly sensitive Anca et al. fabricated NH detectable chemical sensors
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flexible ethanol sensor was developed using inkjet printing, using laser-induced forward transfer printing. The minimum
functionalized with poly(3,4-ethylenedioxythiophene) detectable NH value was 25 ppm, with a response time of 13
3
and carboxylic acid (COOH) poly (styrenesulfonate) s, showcasing an expansion of the manufacturing process.
(PEDOT: PSS) CNT. It exhibits a sensitivity (ΔS/ΔC) of (b) Strain sensors
24.4×10 and short response/recovery times of 13/60 at
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1000 ppm. Its high sensitivity is anticipated to lead to The strain-sensitive property of an object, influenced
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the development of precise ethanol sensors. In addition, a by its structure, undergoes changes when subjected to
humidity sensor was developed using graphene-carbon ink mechanical forces such as tension or compression. This
through screen printing on substrates such as glossy paper, alteration in the property enables accurate measurement
matt paper, and sylvicta. The sensor resistance-humidity of strain experienced by the object.
gradient was approximately 12.4 Ω/%RH (room humidity) Flexible strain sensors were developed using CNT ink
from 25% RH to 91.7% RH. It displayed flexibility, stability, with multiwall nanotubes and PVP through meniscus-
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repeatability, durability, and short response/recovery time. guided printing based on the principle of piezoresistivity.
Detecting humidity is essential across diverse industries, This sensor achieved gauge factors of 12.87 at compressive
environmental monitoring, and health-care sectors, making strain and 13.07 at tensile strain and maintained its

Volume 3 Issue 2 (2024) 17 doi: 10.36922/msam.3323