Three types of textured indium-tin-oxide （ITO） surface, including nano-texturing and hybrid micro/nano-texturing with micro-holes （concave-hybrid-pattem） or micro-pillars （convex-hybrid-pattern）, were applied to...Three types of textured indium-tin-oxide （ITO） surface, including nano-texturing and hybrid micro/nano-texturing with micro-holes （concave-hybrid-pattem） or micro-pillars （convex-hybrid-pattern）, were applied to GaN-based light-emitting diodes （LEDs）. The nano-texturing was realized by maskless wet-etching, and the micro-texturing was achieved by standard photolithography and wet-etching. Compared to LED chips with flat ITO surface, those with nano-pattern, concave-hybrid-pattern, and convex-hybrid-pattern exhibit enhancement of 11.3%, 15.8%, and 17.9%, respectively, for the light-output powers at 20 mA. The electrical performance has no degradation. Moreover, the convex-hybrid-pattern show higher light-output efficiency under small injection current, while the concave-hybrid-pattern exhibit better light-output efficiency at large injection current. The light- extraction efficiency is simulated by use of two-dimensional finite difference time domain method, and the numer- ical results are consistent with the experiments.展开更多
Optogenetics enables precise,cell-specific control of neural activity,surpassing traditional electrical stimulation methods that indiscriminately activate nearby cells,making it crucial for rehabilitation,neurological...Optogenetics enables precise,cell-specific control of neural activity,surpassing traditional electrical stimulation methods that indiscriminately activate nearby cells,making it crucial for rehabilitation,neurological disorder treatment,and understanding neural circuits.Among light sources for delivering light to genetically modified cells,bio-implants integrated with Light Emitting Diodes(LEDs)have recently been the focus of extensive research due to their advantage of enabling local photogeneration.Unlike laser-based systems,which require tethered setups that hinder behavioral experiments,μ-LED-based devices allow for wireless operation,facilitating more natural movement in subjects.Furthermore,μ-LED arrays can be designed with higher spatial resolution compared to waveguide-coupled external light sources,enabling more precise control over neural activity.This paper presents design rules for implantable flexible optogenetic devices based onμ-LED,tailored to the unique anatomical and functional requirements of various regions of the nervous system.Integration of recent advancements in devices withμ-LEDs(e.g.wireless systems,optofluidic systems,multifunctionality,and closed-loop systems)enhances behavioral experiments and deepens understanding of complex neural functions in the brain,spinal cord,autonomic nervous system,and somatic nervous system.The combination of optogenetics with advanced bio-implantable devices offers promising avenues in medical science,providing more effective tools for neuromodulation research and clinical applications.展开更多
基金Project supported by the National High Technology Research and Development Program of China(No.2014AA032609)the Strategic Emerging Industry Special Funds of Guangdong Province(Nos.2010A081002009,2011A081301004,2012A080302003)the Fundamental Research Funds for the Central Universities(Nos.2013ZM093,2013ZP0017)
文摘Three types of textured indium-tin-oxide （ITO） surface, including nano-texturing and hybrid micro/nano-texturing with micro-holes （concave-hybrid-pattem） or micro-pillars （convex-hybrid-pattern）, were applied to GaN-based light-emitting diodes （LEDs）. The nano-texturing was realized by maskless wet-etching, and the micro-texturing was achieved by standard photolithography and wet-etching. Compared to LED chips with flat ITO surface, those with nano-pattern, concave-hybrid-pattern, and convex-hybrid-pattern exhibit enhancement of 11.3%, 15.8%, and 17.9%, respectively, for the light-output powers at 20 mA. The electrical performance has no degradation. Moreover, the convex-hybrid-pattern show higher light-output efficiency under small injection current, while the concave-hybrid-pattern exhibit better light-output efficiency at large injection current. The light- extraction efficiency is simulated by use of two-dimensional finite difference time domain method, and the numer- ical results are consistent with the experiments.
基金support received from the National Research Foundation of Korea(Grant Nos.RS-2024-00353768 and RS-2024-00400874)supported by the Yonsei Fellowship,funded by Lee Youn Jae+1 种基金supported by the WISH Center at Georgia Tech Institute for Matter and Systemssupported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(RS-2024-00464654).
文摘Optogenetics enables precise,cell-specific control of neural activity,surpassing traditional electrical stimulation methods that indiscriminately activate nearby cells,making it crucial for rehabilitation,neurological disorder treatment,and understanding neural circuits.Among light sources for delivering light to genetically modified cells,bio-implants integrated with Light Emitting Diodes(LEDs)have recently been the focus of extensive research due to their advantage of enabling local photogeneration.Unlike laser-based systems,which require tethered setups that hinder behavioral experiments,μ-LED-based devices allow for wireless operation,facilitating more natural movement in subjects.Furthermore,μ-LED arrays can be designed with higher spatial resolution compared to waveguide-coupled external light sources,enabling more precise control over neural activity.This paper presents design rules for implantable flexible optogenetic devices based onμ-LED,tailored to the unique anatomical and functional requirements of various regions of the nervous system.Integration of recent advancements in devices withμ-LEDs(e.g.wireless systems,optofluidic systems,multifunctionality,and closed-loop systems)enhances behavioral experiments and deepens understanding of complex neural functions in the brain,spinal cord,autonomic nervous system,and somatic nervous system.The combination of optogenetics with advanced bio-implantable devices offers promising avenues in medical science,providing more effective tools for neuromodulation research and clinical applications.
