Inventors Use Nanotechnology to Make a Hearing Aid Smaller Than a Coffee Bean

Some say bigger is better, but when it comes to technology in or around the body, smaller is usually more comfortable. And since hearing aids are usually worth more than 20 times their weight in gold, there's definitely an advantage going to the team that can make the smallest version available.

With that inspiration in mind, a team of inventors and industrial designers is using shrinking nanotechnology to create an "the contact lens of hearing aids."

The "Nanoplug," seen between a coffee bean and a single grain of rice (Image source: Nanoplug)

"The device is half the size of the smallest devices currently on the market," said Johnga Lee, industrial designer of the "Nanoplug." "We've spent a year designing and prototyping the smallest hearing aid in the world."

The device works by using a small microphone to collect sounds from the environment. A microchip then converts the incoming sound into digital code; the Nanoplug then analyzes and adjusts the sound based on the users's hearing loss, listening needs and the level of the sounds in the surrounding environment. The signals are then converted back into sound waves and delivered to the eardrum through a receiver.

"The secret of Nanoplug is in its microcomponents," Lee said. "With the longest part only 6.1 millimeters in length, it is completely hidden when inserted into the ear."

Image source: Nanoplug

Creating the audio components is one challenge, but designing and producing a comfortable casing that won't damage the ear canal is another hurdle; but the industrial designers were able to use micro-injection molding to craft the Nanoplug cover.

"Micro-injection molding is a processing technology using extremely high pressure and speed in producing very small and accurate molded parts ... [using] raw materials ranging from high-temperature resistant engineering plastics to commodity resins," the Nanoplug team says. This advanced technique can produce "walls" -- or tiny plastic layers -- as thin as 0.3 mm. "[The device is] a huge leap forward in design, eliminating embarrassment and social stigma."

Since a gadget this tiny will naturally have a smaller battery -- in fact, their prototype uses a battery just slightly larger than a few grains of sand -- one might assume the hearing aid would run out of juice sooner. Not so, says the Nano team.

"With its extremely high surface to volume ratio, it provides a virtually instantaneous recharge [and the] batteries contain no toxic chemicals or heavy metals ... they are integrated and rechargeable," the Nanoplug page explains. The micro-sized battery would give the user 138.888 hours runtime, or roughly six days of use before needing to be recharged.

To accurately grasp the scale, Nanoplug inustrial designer Jongha Lee says "you might compare the battery to a grain of sand." (Image source: Nanoplug)

Because of the unique design and production, the Nanoplug isn't a product you'll find in a store. The inventors are using the crowdfunding site Indiegogo to bring the tiny hearing aid into full production. Early investors can claim their Nanoplug for just over $250.

Accessing hearing aids via social funding platforms may be the best approach for those who simply can't afford the average Food and Drug Administration-approved hearing aids that cost upwards of $2,000 apiece. Gary Shaprio, president and CEO of the Consumer Electronics Association, wrote in an opinion piece for the Hill earlier this year that despite technological advances, FDA restrictions on hearing aids essentially haven't changed since the 1970s.

Check out the inventors' video for the Nanoplug:

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