- Borosilicate Glass
- Iron Alloys
When it comes to going “green” with electronic products, the goal is to minimize energy use and have less of an impact on the environment than traditional electronics. This could mean less energy used while mining materials and manufacturing the device, or it could mean that lifetime usage of the products made from these materials requires less energy.
Less impact on the environment typically entails less toxicity as well, especially after disposal. Recycling is a big key to achieving this. E-waste is a growing problem, its dangers stemming from elements such as lead, cadmium, copper, beryllium, barium, and chromium entering the ecosystem through improperly discarded electronics.
Many of these elements are used in circuit boards and electrical parts such as computer chips, touchscreens, and wiring.
While it may be cheaper to use materials considered to be relatively more toxic options, many electronics producers are choosing to invest in greener materials at the behest of the consumer.
What are some “green” materials used in electronics?
Green materials come in many forms. They can range from degradable circuit boards and organic electronics to metals that are infinitely recyclable and reusable. Organic and inorganic materials can both be considered green, depending on the type of material and how it is implemented.
- On the inorganic side, aluminium is considered a “green metal” due to its recyclability and incredibly long lifespan.
- Borosilicate glass and graphene are other examples of eco-friendly, non-biological materials used in electronics.
Known for its heat resistance and physical durability, borosilicate glass is useful in many applications mostly involved with temperature changes. The material owes its strength and resistance to its unique combination of silica, boric oxide, among various other oxides. The presence of boron oxide to replace some of the oxide components enhances the binding forces within the glass material. Learn more about borosilicate glass.
Aluminium is one of the most ubiquitous metals in the modern world, thanks to properties like high strength-to-weight ratio, high thermal and electrical conductivity, atmospheric corrosion resistance, workability and formability. These properties make it an ideal choice in applications as varied as the aerospace and construction industries, high-tech electronics, high voltage power lines, and more. These characteristics, along with its high recyclability, help improve life-cycle management, and reduce the overall economic and environmental impact of its application. Check properties of aluminium on Matmatch.
As for organic materials, silk is a great green material due to its biodegradability, biocompatibility, and wide range of potential uses. Resins, gums, saccharides, cellulose, gelatine and peptides, which are all biodegradable, are becoming more popular for use in applications such as sensors, signal transducers, transient, implantable and digestible electronics.
What are the benefits of using these materials?
Besides being better for the planet, greener materials often perform just as well as their cheaper, more problematic alternatives. If quality is equal, any company would be smart to market the greener materials used in its products. Consumers are becoming more conscious about how their purchases affect the environment, and showing the environmental benefits of green materials will often lead to higher sales.
In regards to cost benefits, energy efficiency saves money, meaning production can potentially be cheaper using greener methods. There are also “green electronics”, in which the materials themselves are not green or eco-friendly. Rather, their main focus is on front-end energy efficiency, helping consumer lifestyles become greener.
Favourable materials used in “green” electronics
- Borosilicate Glass
- Iron Alloys
Aluminium is known as the “green metal” and “the best eco metal”, though this is not necessarily due to its inherent properties. It’s due to the fact that aluminium has a virtually infinite lifespan. It can be recycled repeatedly without losing any quality.
Each metric tonne of recycled aluminium saves 9 t of CO2 emissions and prevents having to source new raw metal from the ground, which is an expensive and lengthy process. In contrast, a recycled aluminium can is able to be processed and returned to the shelf in as little as six weeks.
On top of its unparalleled recyclability, aluminium is lightweight with incredible strength. Practically, the average density of aluminium is between 2.6 to 2.8 g/cm³, yet tensile strength of pure aluminium is around 90 MPa, which can be increased to over 690 MPa in some alloys.
Strength is important for use in electronics, but its resistance to corrosion is arguably a more valuable trait. Pure aluminium also has an electrical conductivity of about 38 million S/m, while alloys can have a lower conductivity, but rarely as low as that of iron or steel.
- Density: 2.7 g/cm³ at 20 °C
- Elastic modulus: 70 GPa at 20 °C
- Hardness, Brinell: 245 [-] at 20 °C
- Poisson’s ratio: 0.35 [-] at 20 °C
- Tensile strength Rm: 90 MPa at 20 °C
- Melting point: 660 °C
- Specific heat capacity: 900 J/(kg·K) at 20 °C
- Thermal conductivity: 221 W/(m·K) at 20 °C
- Electrical resistivity: 2.6E-8 Ω·m at 20 °C
Borosilicate glass is stronger and has the potential to be used for more applications, especially in electronics. Its strength, durability, and resistance to temperature change result in less replacement and, therefore, less waste. Glass is also a much better alternative than plastic for the environment. Whenever glass can replace plastic in electronics, without losing out on performance, the resulting product will have more “green” value.
This special type of glass is produced from melting the following substances (with corresponding approximate composition): silica sand (59.5%), boric oxide (21.5%), potassium oxide (14.4%), zinc oxide (2.3%), and trace amounts of calcium oxide and aluminium oxide. Continue reading.
Iron isn’t so much a “green” material as it is a “yellow” one, in the sense that it isn’t necessarily good or bad for the environment. Iron ore is the fourth most abundant element in the earth’s crust. If discarded in its pure form, iron does not possess any glaring environmental challenges. Iron alloys, however, are not pure iron – some of them, such as steel, are created using carbon, which doesn’t create any toxicity issues.
The main reason for including iron alloys in this list is its recyclable properties. This is especially pertinent for electronics where recycling is crucial to avoid environmental degradation – and recycling of iron is needed to mitigate the impacts associated with mining new metals that would instead be used. Compared with other heavy metals, iron is the most environmentally friendly.
Two-dimensional and incredibly useful, this material is essentially one atom thick. It’s made solely of carbon atoms arranged in a hexagonal lattice, like a honeycomb.
Graphene possesses several characteristics, including:
- high electron mobility that is 100x faster than silicon
- thermal conductivity 2x better than diamond
- electrical conductivity 13x better than copper
- absorption of only 2.3% of reflecting light
Graphene can be used in a myriad of electronics applications from faster transistors and bendable phones to improved touch screens and advanced circuitry for computers.
Given that it is made from one of the most abundant elements on earth, which also happens to be the element on which all known life is built upon, it is inherently environmentally-friendly. However, the real issue comes from how it is produced: if it’s made using solvents and chemicals, it loses its “green” status due to toxicity in its upstream production.
But if it is made using physical processes, with no related chemical discharge to the surrounding environment, then it can live up to its reputation as the wonder-material that it has been dubbed.
Biomaterials are becoming more useful as electronics become more wearable, stretchable, and integrated with organic substances. Silk is especially useful in bio-sensor and implantable thermoelectric wireless switching applications. In one interesting example, a team from Florida State University placed silk in a vacuum chamber and coated it with gold, creating a hybrid fibre measuring 4% the width of a human hair.
Since standard wires made of gold or other metals aren’t elastic enough, they tend to lose contact with soft organic crystals as temperatures change. The gold coated silk changes this, combining the conductivity of gold with the flexibility of silk.
“Green” electronics are becoming more ubiquitous
As consumer demand continues to grow for more environmentally-friendly products, and as the line continues to blur between electronic and organic, “green” materials will become even more prevalent in electronics production.
Whether it’s in the form of wearable tech or more ecologically-friendly products, we will likely see electronics that are continually better for the environment. As long as the demand for “green products” keeps growing, expect the electronics industry to appease the consumer – and in some cases improve their own products, as well.