By Taha KhanReviewed by Lexie CornerOct 28 2024
Electronic materials are selected, designed, or engineered for specific properties like conduction, insulation, magnetism, or energy storage in electronic applications.1 They are fundamental to nearly all modern technologies.
Image Credit: Muravev Dmitriy/Shutterstock.com
Types of Electronic Materials
Conductors
Conductors are materials that allow electric current to flow with minimal resistance and are essential for transmitting power and electrical signals in electronic devices. Most metals are good conductors of electricity, with copper, aluminum, and silver being commonly used due to their critical role in modern electronics.2
At an atomic level, metals have a high density of loosely bound valence electrons that can move freely throughout the material, enabling efficient current flow with minimal resistance under applied potential. Conductor effectiveness also depends on factors such as electron mobility, atomic structure, and thermal stability. For example, copper combines high electron mobility with low atomic mass, facilitating efficient charge transfer.
Conductors are used in nearly all electronic devices. Electricity travels from grid stations to homes through conductor wires, which power electronic devices. For instance, copper and silver are widely used in electrical wiring because they transmit electric power with minimal energy loss. Similarly, in printed circuit boards (PCBs), thin copper pathways connect components.
Conductors are also used for electromagnetic shielding, protecting sensitive components in telecommunications and aerospace from electromagnetic interference, which can disrupt or degrade the performance of electronic systems.
Novel Conductive Materials
When we think of conductors, metals are typically the first materials that come to mind. However, recent advancements have introduced conductive polymers, which provide flexible, lightweight alternatives to metals.
Innovations in nanomaterials such as graphene, copper nanoparticles, and carbon nanotubes have further enhanced conductor performance. These advanced materials are particularly advantageous in applications such as wearable electronics and flexible displays.
For instance, a recent study synthesized oxidation-resistant copper nanoparticles with a high conductivity and low resistivity of 1.67 × 10⁻³ Ω cm, demonstrating their potential in flexible electronics.3
Insulators
Insulators have properties opposite to those of conductors, as they prevent the flow of electric current where it is necessary to stop it. They are equally important, providing essential isolation between conductive components to prevent electrical short circuits and ensure safety.2
In insulators, electrons are confined within filled valence bands, with a large band gap separating the valence band from the conduction band. This substantial band gap requires a high amount of energy to excite electrons to a conductive level, effectively preventing electrical current flow under typical conditions.
Insulators are used extensively in power systems, electronic devices, and high-voltage transmission lines. Exposed live wires carrying electric current can be hazardous upon contact. To prevent electric shocks and short circuits, materials like plastic and rubber are used to coat these wires, providing essential protection.
Insulators, such as ceramics, are also used as dielectric materials in capacitors, storing electrical energy without allowing leakage currents. They also serve as substrates in circuit boards and as protective coatings for electronic components.
Recent Developments in Electrical Insulators
Recent research has focused on developing more efficient and durable insulating materials that can withstand high temperatures and harsh environments, with nanotechnology playing a key role. In one study, researchers enhanced the thermal, electrical, and mechanical properties of cross-linked polyethylene (XLPE) by incorporating inorganic nanoparticles like silicon dioxide (SiO2).
XLPE is commonly used in high-voltage cables, but its insulating properties can degrade over time due to environmental factors such as heat and humidity. The study investigated both functionalized and non-functionalized SiO₂ nanoparticles, finding that functionalized nanoparticles offered superior dielectric strength, breakdown resistance, and mechanical stability.
This performance improvement results from better dispersion of functionalized nanoparticles within the XLPE matrix, which reduces particle agglomeration and strengthens interfacial bonding. Optimized dispersion also limits polymer chain mobility, enhancing resistance to electrical stress. However, at higher nanoparticle concentrations, agglomeration can occur, diminishing these benefits.4
Semiconductors
Semiconductors are materials with electrical conductivity between that of conductors and insulators. Materials like silicon, germanium, and gallium arsenide exhibit selective conductivity due to their atomic structure, where electrons in the valence band require an energy input from heat or light to move into the conduction band.
Semiconductors are tunable; through a process called doping, impurities are added to adjust electrical properties, creating n-type or p-type semiconductors with distinct charge carriers (electrons for n-type and holes for p-type). This customization enables precise control of conductivity, making semiconductors essential for electronic devices, as they form the basis of transistors, diodes, and integrated circuits (ICs).
Transistors, the core components of digital circuits, function as switches or amplifiers in electronic circuits and are fundamental to devices ranging from simple calculators to advanced computers.
Diodes, also made from semiconductors, are used in AC-to-DC conversion, voltage regulation, signal modulation, and light detection in photodiodes. ICs—comprising transistors, capacitors, resistors, and other components—are fabricated on a single semiconductor substrate, typically silicon.
Advances in Semiconductor Materials
Silicon is the most widely used semiconductor, but materials like gallium arsenide, silicon carbide, and gallium nitride are becoming increasingly important in advanced applications.
Recent advancements in semiconductor technology have focused on enhancing performance and energy efficiency, with silicon carbide and gallium nitride enabling higher power density for applications like electric vehicles and renewable energy systems.5
Magnetic Materials
Magnetism is an important phenomenon in modern electronics, with materials such as iron, cobalt, and nickel being important for generating and controlling magnetic fields in devices.
Magnetic materials are widely used in data storage devices, sensors, and electric motors. For instance, magnetic materials are used in hard drives, where data is stored in magnetic domains on spinning disks. Magnetic materials are also used to convert electrical energy into mechanical energy, making them essential in applications like electric motors, transformers, fuel ignition systems, and electric vehicles.
Next-Generation Magnetic Materials for Electronics
A type of magnetic material known as spinel-structured ferrites has recently gained attention for its potential in various applications, including data storage, high-density magnetic recording, solar cells, sensors, and actuators.
Spinel ferrites are notable for their high electrical resistivity, low energy losses at high frequencies, and chemical and thermal stability. Their tunable magnetic properties and cost-effectiveness make them valuable for use in telecommunications, medical technology, and high-frequency electronics.6
Piezoelectric Materials
Piezoelectric materials, such as lead zirconate titanate (PZT) and quartz, generate an electric charge when exposed to mechanical stress. This effect results from their internal structure, where ion displacement within the crystal lattice under pressure creates charge separation.
Conversely, when an electric field is applied, these materials undergo mechanical deformation. This dual behavior makes piezoelectric materials valuable in applications requiring both sensing and actuation.
For example, in medical ultrasonography, piezoelectric crystals convert electrical signals into high-frequency sound waves, which then reflect back and are converted into electrical signals to produce an image.
Medical Applications
In a 2021 study, researchers investigated a flexible piezoelectric transducer for sonomyography to enhance muscle activity assessment in ultrasonography. They designed a single-element transducer featuring a 66 μm thick PZT-5H layer with a polymer backing substrate, using COMSOL Multiphysics® simulations to improve flexibility and charge accumulation.
Preliminary simulations showed promising ultrasound transmission across a broad frequency range (200 kHz to 30 MHz). This development could advance applications in diagnostics, prosthetic control, and rehabilitation engineering by providing detailed, real-time muscle data.7
Outlook on Electronic Materials
Electronic materials are central to modern technology, supporting key advancements in computing, communication, renewable energy, and healthcare. Continued progress in materials science is making electronic devices faster, smaller, and more energy-efficient.
The future of these materials is closely linked to developments in nanotechnology, spintronics, artificial intelligence, and quantum computing, which offer opportunities to enhance existing materials and create new ones with improved properties.
Perovskite Quantum Dots: Transforming the Landscape of Optoelectronics
References and Further Reading
- Li, Z., Gao, W. (2008). Oxidation processing of electronic materials. In W. Gao & Z. Li (Eds.), Developments in high temperature corrosion and protection of materials. Woodhead Publishing. https://doi.org/10.1533/9781845694258.3.521
- Levit, L., Steinman, A. (2008). ESD controls in cleanroom environments: Relevance to particle deposition. In R. Kohli & K. L. Mittal (Eds.), Developments in surface contamination and cleaning. William Andrew Publishing. https://doi.org/10.1016/B978-0-323-29960-2.00006-X
- Hong, GB., Wang, JF., Chuang, KJ., Cheng, HY., Chang, KC., Ma, C. M. (2022). Preparing copper nanoparticles and flexible copper conductive sheets. Nanomaterials. https://doi.org/10.3390/nano12030360
- Said, AR., Nawar, AG., Elsayed, AE., Abd-Allah, MA., Kamel, S. (2021). Enhancing electrical, thermal, and mechanical properties of HV cross-linked polyethylene insulation using silica nanofillers. Journal of Materials Engineering and Performance. https://doi.org/10.1007/s11665-021-05488-8
- Letellier, A., Dubois, MR., Trovao, JP., Maher, H. (2015). Gallium nitride semiconductors in power electronics for electric vehicles: Advantages and challenges. IEEE vehicle power and propulsion conference (VPPC). https://doi.org/10.1109/VPPC.2015.7352955
- Oh, Y., Sahu, M., Hajra, S., Padhan, AM., Panda, S., Kim, HJ. (2022). Spinel ferrites (CoFe2O4): synthesis, magnetic properties, and electromagnetic generator for vibration energy harvesting. Journal of Electronic Materials. https://doi.org/10.1007/s11664-022-09551-5
- Sanchez, MC., Zuo, S., Moldovan, A., Cochran, S., Nazarpour, K., Heidari, H. (2021, November). Flexible piezoelectric sensors for miniaturized sonomyography. IEEE. https://doi.org/10.1109/EMBC46164.2021.9630342
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.