Higher wear comfort and functionality with 3-D printed otoplastics
10/09/2015

Figure caption 1: Participants at the Kick-Off-Meeting in July, in front of the Sennheiser Innovation Campus. (Photo: Sennheiser)

Wear comfort and excellent sound transmission are essential for people who use in-ear hearing aids or headsets. Since June 2015, the Laser Zentrum Hannover e.V. (LZH) and seven partners have been working in the group 3D-PolySPRINT on increasing both the functionality and wear comfort, and simultaneously on reducing delivery times. They are focusing on non-tactile imaging and combined multi-material 3-D printing processes in order to manufacture otoplastics which are optimally adapted to the auditory canal.

For a hearing aid or an individualized in-ear-headset, presently a mold of the ear is made, then digitized and finally used to manufacture the otoplastic. The project partners of 3D-PolySPRINT want to fundamentally change this approach.

Digital Mold of the Auditory Canal
Using the non-tactile imaging method of optical coherence tomography (OCT), they want to make a digital image of the auditory canal without having to make a mold. First the ear is optically scanned, and the form is digitized. For the next step, the group Image-Guided Laser Surgery of the LZH is developing a software which converts the raw image data of the scan to a construction file. Once in the computer, the data can be further processed quickly, and molds do not need to be sent to other sites, and then scanned.

A hard core and a soft covering
Using the digitized data of the individual ear, the partners want to optimize both the function and the wear comfort of the ear mold for the customer, and avoid unpleasant pressure sores. To achieve this, the partners are combining two additive manufacturing processes, spray coating and Laser Transfer Printing (LTP), in order to join two different materials together, and to make a hardness profile within the ear mold. The Laser Micromachining Group of the LZH is developing the necessary process, and is examining the new materials concerning their suitability, always keeping the criteria of the end users Sennheiser electronic GmbH & Co KG and KIND Hörgeräte GmbH in mind.

Increasing wear comfort and decreasing delivery times
With this innovative process chain of OCT and 3-D printing, not only the manufacturing of the otoplastics is considerably more pleasant for the customers. Also, the headset or the hearing aid would be usable for longer periods of time, it would provide better sound quality, and it would reach the customer at least a day earlier.

About 3D-PolySPRINT
The joint project 3D-PolySPRINT is being coordinated by the Sennheiser electronic GmbH & Co. KG and consists of the companies KIND Hörgeräte GmbH & Co. KG, OptoMedical Technologies GmbH, Materialise GmbH, Dreve ProDiMed GmbH, microTEC Gesellschaft für Mikrotechnologie mbH, LPKF Laser & Electronics AG and the LZH. The work is being funded within the call for proposals “Photonic Process Chains” within the framework of the programs “Photonic Research Germany” and “Material Technologies for Industry and Society (WING)” through the German Federal Ministry of Education and Research, and will be running for three years.

There is one figure for this press release.

Figure caption 1: Participants at the Kick-Off-Meeting in July, in front of the Sennheiser Innovation Campus. (Photo: Sennheiser)

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Laser Zentrum Hannover e.V. (LZH)

As an independent, non-profit research institute, the Laser Zentrum Hannover e.V. (LZH) stands for innovative research, development and consulting. The LZH is supported by the Lower Saxony Ministry for Economics, Labour and Transport and is dedicated to the selfless promotion of applied research in the field of photonics and laser technology. Founded in 1986, over 170 employees are now working for the LZH.

The focus of the LZH lies on the fields of optical components and systems, optical production technologies, and biomedical photonics. Interdisciplinary cooperation between natural scientists and mechanical engineers makes innovative approaches to challenges from the most different areas possible: from the development of components for specific laser systems to process developments for the most diverse laser applications, for example for medical technology or lightweight construction in the automotive sector. Seventeen spin off companies have emerged from the LZH up to now. Thus, the LZH has created a strong transfer between fundamental science, application oriented research, and industry.