OLED-on-CMOS technology: New approach for light sources

Optogenetics makes it possible to control genetically modified cells using light. By introducing light-sensitive proteins into cells, researchers can specifically switch their activity on and off with light pulses. This technique is widely used in neuroscience to investigate the functions of nerve cells and to activate or inhibit specific neurons in a targeted manner. Small and selective light sources are essential here in order to trigger precise cell reactions. 

OLED-on-silicon technology makes it possible to place tiny, selectively controllable light pixels on a chip. “With OLED-on-silicon technology, we can bring tiny, locally controllable light pixels onto a chip. This chip can be flexibly designed to reach the desired locations even in curved structures like the cochlea. This allows light to be used precisely where electrical stimulation alone is insufficient,” explains Dr. Uwe Vogel, Head of the ‘Microdisplays and Sensors’ Business Unit at Fraunhofer IPMS. 

In the “NeurOpto” project, OLED-on-CMOS technology is being further developed for oCIs. This technology was initially developed at Fraunhofer IPMS for microdisplays and enables CMOS-integrated light sources with high pixel density, brightness and low power consumption. The aim is to create a pixelated OLED microprobe that can be controlled via a serial interface to project light pulses precisely along the frequency axis of the cochlea. 

The OLED-on-CMOS technology has been successfully tested in terms of brightness and level of integration. However, challenges remain in the flexibility of the probes and their biological compatibility, which are crucial for use in the human body. 

The technology has the potential to be used not only for cochlear implants, but also for other medical applications. Prof. Tobias Moser explains: “Intelligent implantable stimulators based on optical stimulation could also be used for other medical therapies such as laryngeal pacemakers, cardiac pacemakers, pain relieve, retinal implants, or deep brain stimulation.” 

The “NeurOpto” project has taken the first steps towards using OLED-on-CMOS technology in optogenetics. The technology is being further developed and the researchers are also open to applications in other medical fields. Although market maturity will still take some time, the results so far show promising potential. 

COMPAMED-tradefair.com; Source: Fraunhofer Institute for Photonic Microsystems