Acta Phys. -Chim. Sin. ›› 2020, Vol. 36 ›› Issue (12): 1912054.doi: 10.3866/PKU.WHXB201912054

Special Issue: Neural Interfaces

• REVIEW • Previous Articles     Next Articles

Development of Implantable Optrode Devices

Yamin Li1,3, Yang Wang1,2, Hongda Chen1,3, Yijun Wang1,3, Yuanyuan Liu1,3, Weihua Pei1,3,4,*()   

  1. 1 State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
    2 School of Microelectronics, University of Sciences and Technology of China, Hefei 230000, P. R. China
    3 University of Chinese Academy of Sciences, Beijing 100049, P. R. China
    4 CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai 200000, P. R. China
  • Received:2019-12-23 Accepted:2020-01-24 Published:2020-03-03
  • Contact: Weihua Pei
  • Supported by:
    The project was supported by the National Key R & D Project of China(2017YFA0205903);The project was supported by the National Key R & D Project of China(2017YFA0701100);The project was supported by the National Key R & D Project of China(2016YFB0402405);National Natural Science Foundation of China(61634006);National Natural Science Foundation of China(61335010);National Natural Science Foundation of China(61671424);Strategic Priority Research Program of Chinese Academy of Science(XDB32030100);Strategic Priority Research Program of Chinese Academy of Science(XDB32040200)


Optogenetics transforms specific types of neurons through genetic engineering to achieve the cell membrane expression of photosensitive channel protein. When a specific wavelength of light irradiates the photosensitive channel protein, the cell is either excited or inhibited. Optogenetics provides a precise and fast method to control the activity of individual neurons for neuroscience research, which has gained increasing attention as a means of neural regulation. To realize the photogenetic regulation of neurons, light should be introduced into the brain safely and efficiently. Thus, specialized photoelectric devices are needed. Optrode plays a significant role in the application of optogenetics tools, which is the technical basis for the application of optogenetics. Optrode is a kind of implantable neural interface device. It can introduce light into the brain to regulate neural activity and record the changes of neural electrical signals under the control of lights. As the research of optogenetic technology continues, More and more optrodes are being developed and applied in the study of neuroscience and diseases, such as neural circuit, cognition and memory, epilepsy, and sensory function damage. The combination of optrode with optogenetic technologies provides various developmental modes in terms of material selection, device structure, light supply method, and integrated ways. The difficulty in fabricating optrodes lies in performing light stimulation and electrical signal recording without causing the immune rejection of the test animal and affecting its normal physiological activities simultaneously. In this study, based on structural characteristics and manufacturing process, optrodes are classified into two categories: waveguide-based and micro-light emitting diode-based. Subsequently, based on manufacturing process and light supply method, waveguide-based optrodes are further divided into optical fiber-optrode, optical waveguide-optrode based on MENS technology, and LD/LED waveguide-optrode. Similarly, micro-light emitting diode-based optrodes are divided into hard μLED optrode and soft μLED optrode. The advantages and disadvantages of different types of optrodes, as well as the evolution direction, are reviewed and summarized. Additionally, problems with existing optrodes, such as signal quality, biocompatibility, and device reliability, are discussed. Further, the ideal form of the device is presented as possessing the following characteristics: μLED and recording electrode integrated on flexible substrate, small size, high spatial resolution, high biocompatibility, wireless energy supply, wireless data transmission, etc. As optrode technologies are continuously updated, in the application of optogenetic technologies, research on brain neural circuit and functional structure will be better studied, and various nerve diseases will be gradually tamed.

Key words: Optogenetics, Optrode, Action potential, Optical waveguide, Micro-Light emitting diode