Selective Edge Rounding of Cyclic Olefin Copolymer Film Using UV Laser for Implantable Electrode Package.

Cyclic Olefin Copolymer is emerging as a packaging material for implantable electrodes due to its physical properties such as low water absorption rate and low water vapor permeability. The electrode-tissue interface is often regarded as a major focus of implantable electrodes, but its packaging should also be considered thoroughly since it directly contacts the adjoining body cells. Therefore, eliminating any sharp boundaries or edges around the package would be beneficial to minimize potential inflammatory responses caused by physical/mechanical stresses. To smooth both inner/outer edges of a cyclic olefin copolymer packaging, an optimal UV laser condition was investigated by varying its marking speed and iterations. Clinical relevance - This establishes a method that can selectively smooth the edges around a cyclic olefin copolymer pack-aged implantable electrodes for reduced mechanical mismatch after insertion.

Low-cost, thermoplastic micro-lens array with a carbon black light screen for bio-mimetic vision.

Micro-lens array is a great example of bio-mimetic technology which was inspired by compound eyes found in insects and is used in lasers, optical communication, and 3D imaging. In this study, a micro-lens array was fabricated from cyclic olefin copolymer using a cost-effective method: compression molding and thermal reflow. Also, a light screen was installed between lenses to reduce the optical interference for clearer individual images. Cyclic olefin copolymer-based micro-lens array showed good optical results under a standard optical microscope. By placing the fabricated micro-lens array directly on an image sensor, it was observed that the light screen shows significant improvement in image quality. Also, the point spread function was analyzed to confirm the optical performance and the effectiveness of the micro-lens array with the light screen installed.

Fabrication of a light screen-aperture integrated flexible thin film micro-lens array for a biomimetic superposition compound eye.

Micro-lens array, an artificial compound eye vision system, provides a wide field of view and multi-perspective view. However, it has not been adopted as a computer vision application due to its limited visible range and high optical interference. In this research, a novel fabrication method for the flexible polydimethylsiloxane micro-lens array with a polytetrafluoroethylene light screen-aperture integrated layer was established by the simple protrusion method. The integrated layer provided longer visible range by one meter while maintaining the wide field-of-view of 100 °. The resulting images were used for obtaining depth information of a target as an example and for analyzing the rectangular and hexagonal arrangements of the micro-lenses for the future applications. With the improved visual range, wide field-of-view and flexibility, the fabricated micro-lens array can be applied to the small and curved CMOS image sensors in the future.

Artificial Compound Eye Systems and Their Application: A Review.

The natural compound eye system has many outstanding properties, such as a more compact size, wider-angle view, better capacity to detect moving objects, and higher sensitivity to light intensity, compared to that of a single-aperture vision system. Thanks to the development of micro- and nano-fabrication techniques, many artificial compound eye imaging systems have been studied and fabricated to inherit fascinating optical features of the natural compound eye. This paper provides a review of artificial compound eye imaging systems. This review begins by introducing the principle of the natural compound eye, and then, the analysis of two types of artificial compound eye systems. We equally present the applications of the artificial compound eye imaging systems. Finally, we suggest our outlooks about the artificial compound eye imaging system.

Stretchability enhancement of electronics according to the surface patterns fabricated by thermal reflow process.

Fabricating flexible and stretchable substrate for circuits is very important to make biomedical devices like biosensors or neural prosthesis. In this paper, the resistance changes of the polydimethylsiloxane (PDMS) film are observed when it is stretched. And the stretchability is measured and classified according to the shape of the engraved patterns. Patterns are fabricated on Si wafer by lithography. Thermal reflow process is conducted to modify the shape of the tips and we used spin coating method to make thin PDMS film. PDMS film is cut into uniform small pieces and stretched at a constant rate by the syringe pump. The resistance of the film is measured while film is stretched. According to the curvature and depth of the groove on the surface, the degree of the improvement varies. The deeper and round patterns enhance the stretchability of the film but sharp and shallow patterns degrade it.

Legal Issues in Implantable Medical Devices: Liability & Hedge.

Recent advances in science and technology led consumers to benefit from better health care system and medical equipment. On the other side of the matter, regulations regarding those technologies emerged to guide sponsors and manufacturers who make the medical devices, as well as participants in clinical evaluation stage. However, as implantable medical devices appear, updated regulations are necessary to avoid potential legal issues in complicated circumstances where it is hard to recognize the implantable medical device as is, but it is closely related to one's life. In this paper, contemporary regulations around the globe are explored and discussed for more sophisticated regulation for future implantable medical devices.