Germany uses optical imaging with 3D printing technology to develop hearing aids

Recently, seven companies from Germany and a nonprofit institute have teamed up to develop a new technology that uses both optical imaging and multi-material 3D printing technology to make both comfort and sound quality fast and completely non-intrusive Good hearing aid.

In fact, the 3D-polysprint project has been available since June last year. The project leaders include headphone and audio specialist Sennheiser Electronic and its 3D printing partner Materialize, a PCB manufacturer LPKF Laser & Electronics, while the independent nonprofit research organization Hannover Laser Center (LZH) helped the project team develop data conversion software.

The eight agencies participating in the project were at the start-up meeting in July in front of the Sennheiser Innovation Park.

The current method used by a manufacturer to make a customized 3D printed hearing aid or in-ear headset is primarily to pour liquid injection molding material into the user's ear, wait for it to harden, and then remove it for its 3D scan, and finally 3D printing. This procedure worked well under some conditions, but still seemed too long and uncomfortable for the patient. The idea behind the 3D-polysprint project team is to fundamentally change this approach by avoiding actual injection molding and relying solely on contactless imaging to create the perfect hearing aid that perfectly matches each patient.

3D printed earplugs with photo-curing technology

According to the development team, this non-contact imaging method is called optical coherence tomography (OCT), where such optical scanning can be used to capture 3D images (ie, the ear canal) of biological tissue at micrometer resolution. The data is then sent to LZH-developed software that transforms the patient's ear canal's raw image data into a 3D-printable model.

OPMed OCT camera for 3D imaging

For the time being, this earplug hearing aid will use 3D printing with spray technology and Laser Transfer Printing (LTP) technology. LZH's laser micromachining team is developing the necessary process that focuses on multi-material 3D printing to achieve a hard core with a soft covering over the surface to improve comfort and prevent unpleasant pressure ulcers.

According to LZH, the combination of optical imaging and 3D printing can be made with a more comfortable hearing device, better sound quality, and customizable to fit everyone's needs, while reducing manufacturing and lead times. More importantly, because the hearing aid is tailor-made and uses a durable material, its lifespan is greatly extended.

The 3D polysprint project is reported to include OptoMedical Technologies, Dreve ProDiMed, microTec Gesellschaft für Mikrotechnologie and Kind Hrgerte GmbH & Co., in addition to Sennheiser Electronic, LZH, Materialise and LPKF mentioned at the outset. The project is also funded by the German Federal Ministry of Education and Research and is expected to last two years. The product eventually developed will be sold by Sennheiser and Kind companies to users all over the world.