The last decade saw the mobile market growth progressively skyrocket. Portable electronic devices such as cell phones, laptops, iPods, tablets, household robots and more have become largely prevalent in everyday tasks and activities of consumers. In the case of mobile phones, the increase is staggering – the latest statistical figures show that the number of mobile phone users across the globe will be more than five billion by 2019.
The truth is that we have become largely dependent on mobile devices, as well as other portable electronics, which all require batteries that need to be recharged often. At best, a fully charged cell phone lasts for a day and laptop charge goes for several hours, resulting in some of these gadgets spending a better part of the day tethered to a wall. Unless you carry your charger with you everywhere, it’s difficult to keep your device battery from dying in the course of a busy day.
But what if you could charge your cell phone, mp3 players, laptop, and other portable electronics conveniently without going through the stress of carrying a charger and looking for a power socket everywhere? A new technology makes wireless power transfer feasible, popping up in cafes, public restaurants, businesses. It’s set to gradually improve the way we keep our mobile devices and everyday technology powered and at our disposal.
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Say Goodbye to Wires
Wireless charging technology, also known as inductive or cordless charging, enables power delivery from an electric source to an electronic device without the need for plugging in or tethering to a connective wire.
The technology can be applied for both low and high power charging. Low power charging cover devices which typically charge at under 100 watts including small consumer electronic devices. This covers cell phones, handheld devices, laptops and more.
On the other hand, high power charging refers to powering batteries at levels beyond 1 kilowatt. The most prominent application area for this case is electric vehicles, as they have power levels that range between 1 to 300+ kilowatts.
A Little Bit of History
To understand the story and science behind wireless charging technology, let’s go back almost 200 years to when Michael Faraday, one of the greatest scientists of the 19th century, made a huge discovery – electromagnetic induction. Faraday identified that an electrical current passed through a coil would generate a short current in another adjacent coil. Later on in the 1890s, Nikola Tesla, an inventor and electrical engineer, utilized Faraday’s idea to demonstrate the phenomena of resonating inductive coupling. Tesla managed to light approximately 200 lamps between two axially aligned coils using magnetic fields over an air gap distance of 25 miles (40 km). His innovation marked the birth, research, and development of wireless energy transfer systems, which has since experienced considerable growth in the last few decades.
In 2007, Tesla’s invention was further developed and popularized by a team at MIT led by Marin Soljacic. Before this development, engineers had not figured out a way to allow high-efficiency energy transfer using the procedure. Soljacic and his team accomplished a 40% energy transfer efficiency by transmitting 60 watts of power over approximately 2 meters.
How Does Wireless Charging Work?
Fast forward to today, wireless charging uses electromagnetic induction to transmit energy wirelessly between two objects.
The technology integrates two inductive coils wrapped in copper wire. One of the coils is contained in a charging base sometimes referred to as a ‘mat’. The mat is responsible for the generation of alternating current (AC). The other coil is usually placed within a portable device that is in need of a charge, say a cell phone, tablet, electric vehicle, etc.
When the power supply to the primary coil/the base/mat is switched on, AC flows through to create an electromagnetic field so that when the secondary coil comes close in proximity, an electric current is generated. Generated AC is usually converted into Direct Current (DC) by the receiver circuit (on the device), which then uses that energy to charge your device battery.
Inductive charging has in the past been used to charge rechargeable toothbrushes. However, other applications including cell phones, laptops, medical implants and electric cars have accelerated its development. Many cell phone companies have started embedding wireless charging into their devices by adopting current wireless charging standards, like the Qi wireless.
The electric car industry has also shown an increased interest in charging vehicles wirelessly. Wireless charging also makes charging biomedical devices, such as pacemakers, easier on patients as they no longer need to have exposed portions of implanted devices.
The result is that many companies are looking to gain dominance and fly the wireless standard banner, including the Wireless Power Consortium, which drives the Qi wireless standard, and Power Matters Alliance, the group behind Power Mat technology.
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Wire-Free Future
Widespread wireless charging technology is indisputably on the horizon. Its mechanism is a clever bit of effective engineering whose steady growth and adoption began in 2015. The demand was driven by advanced electronics technology and consumers wanting more of it in public places and adaptable spaces. Starbucks, McDonald’s, and Ikea have already embraced wireless charging technology into their consumer spaces.
Apple’s iPhone 8 has wireless charging ability and many electronic devices manufacturers, including Android and Samsung, are working to integrate this convenient innovation into their devices. Engineers and tech giants in the industry are pushing themselves to constantly innovate and develop the technology so that it can even be more convenient to access, leading to more benefits including smaller batteries, less hardware, and lower manufacturing costs.
This expected growth in the wireless charging market is currently estimated to surpass 14 billion dollars by 2024. With the increasing number of consumer electronic devices and their associated cables in modern households, going wire-free is a convenient innovation that will increase the demand for better designed mobile devices and personal technology.
