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The increasing digitalization of medical devices is a global trend. The use of medical silicone is also playing an increasingly important role here. Two main approaches can be distinguished:
Encapsulation of electronic components with silicone
So-called wearables such as smart watches, fitness trackers and heart rate monitors are worn directly on the body and monitor vital signs. Silicone insulates the electronic components and sensors, protecting them from dirt, water and sweat. This ensures reliable operation and durability.
Electrically conductive silicone
By combining silicone and conductive fillers, electrical currents can be conducted, and specific parts of the body can be stimulated in a targeted manner. Areas of application include neurostimulation for pain treatment or targeted training of specific muscle groups.
The manufacture of such materials requires not only medical expertise but also a high level of materials development and tooling competence. Freudenberg Medical has many years of manufacturing experience in the field of biocompatible silicones and a high level of expertise in electrical functionalization. Furthermore, the company can specifically overmold electronic components with silicone.
Freudenberg Medical supports Dutch start-up Bambi Medical with innovative silicone solution
The Dutch start-up Bambi Medical has developed the Bambi Belt, an innovative monitoring system for premature babies. The Bambi Belt replaces cumbersome cables and electrodes when monitoring premature babies with a skin-friendly silicone belt with integrated electronic sensors. The soft belt can be put on and taken off without pain or discomfort to the baby, and the sensors integrated into the belt record the baby's vital functions via the skin.
Data transmission by radio instead of cables
The recorded data is transmitted to the monitoring device by radiofrequency. Interfering cables are eliminated, and parents can hold their child normally and make physical contact. This promotes the baby's mental development. Disturbing adhesive electrodes are also eliminated. This is important for the particularly sensitive skin of premature babies to prevent wounds and infections.
Freudenberg Medical is supporting Bambi Medical in the manufacture of the belt with material and process expertise. The Bambi Belt uses platinum-cured, biocompatible silicones of various degrees of hardness, other materials, and sensors. Thorough material analysis and numerous tests were required to ensure that the various materials are compatible with each other and achieve the desired physical properties.
The result is a flexible conductor track coated with various silicones and incorporating sensors, which both adheres well to the skin and can be easily removed. The velvety surface texture is achieved without additional coating, further reducing material and process steps.
The Bambi Belt team is convinced by the belt and the collaboration with Freudenberg Medical: "It is a complex product that did not exist on the market before," says Fabio Bambang Oetomo, CEO and co-founder of Bambi Medical and son of inventor Professor Bambang Oetomo. "The technical challenge was therefore high, but already after developing the first samples we knew we had made the right choice."
Daniel Kaltbeitzel, Head of Engineering at Freudenberg Medical in Kaiserslautern, Germany
The advantages at a glance:
Freudenberg Medical manufactures medical components made of electrically conductive silicone for innovative neuromuscular tongue training device from Signifier Medical Technologies
Many people worldwide suffer from mild obstructive sleep apnea. In addition to reduced sleep quality, sleep apnea is associated with other risks, including high blood pressure and Alzheimer's disease. Among the most common causes of this breathing disorder during sleep is slackened tissue in the nose and throat. However, strengthening the tongue muscle can reduce the problem.
Idea meets materials and process expertise
London-based medical technology company Signifier Medical Technologies is using this insight for its tongue training with the eXciteOSA®. The device is worn in the mouth for 20 minutes a day, where it stimulates the tongue muscle with minimal electric shocks via a smartphone app. The mouthpiece for the eXciteOSA® is manufactured at Freudenberg Medical´s facility in Germany.
The material for the mouthpiece consists of an electrically conductive silicone that Freudenberg has further developed especially for Signifier Medical Technologies. Existing solutions such as graphite fillers were ruled out for a medical mouthpiece due to poor aesthetics, among other reasons. Established modifications with carbon nanotubes (CNTs) also failed to meet the requirements because they could not ensure the necessary conductivity during processing due to high shear forces. For the eXciteOSA®, fine metallic fillers already coated with another metal are mixed into liquid silicone in a specific ratio. When cured, this produces small, conductive silicone pads. Four of these are then inserted per mouthpiece into a lower shell of liquid silicone. Finally, a top shell is added, and the product is overmolded with silicone. Freudenberg Medical tests the electrical functionality of each individual mouthpiece.
High wearing comfort for more well-being and health
"Saliva, temperatures, mouth movements or cleaning agents - they all have an impact on the long-term reliability of the mouthpiece," says Daniel Kaltbeitzel, Head of Engineering at Freudenberg Medical´s German facility. "This has necessitated extensive material testing and analysis to ensure the product's lasting functionality."
In addition, all the tools used to manufacture the mouthpiece first had to be specially developed by Freudenberg Medical. "The platinum-cured electrically conductive silicone is extremely viscous and difficult to process. Standard manufacturing processes and tools are not optimized for these special needs. So, we used our knowledge of process and automation technology to be able to implement the customer's wishes with specially fabricated molds. Our internal Freudenberg business network helped us in this," Kaltbeitzel continued.
Dr. Kai Opdenwinkel, General Manager of Freudenberg Medical in Kaiserslautern, Germany
Freudenberg Medical's expertise in the manufacture of the eXciteOSA®: