Design and characterisation of graphene-based nano-photodiode array device for photo-stimulation of subretinal implant

Micro & nano letters

article

Vijai Meyyappan Moorthy¹  Mary Sugantharathnam²  Joseph Daniel Rathnasami³  Shanmugaraja Pattan³ 

[1] Electronics and Instrumentation Engineering, Annamalai University;Electronics and Communication Engineering, Govt. College of Engineering;NPMaSS MEMS Design Centre, Electronics and Instrumentation Engineering, Annamalai University

关键词: photoconductivity;    eye;    solar cells;    diseases;    graphene;    biomedical electrodes;    prosthetics;    photodiodes;    vision defects;    nanophotonics;    nanomedicine;    single-wall carbon nanotubes;    semiconductor nanotubes;    prosthetic power supplies;    energy harvesting;    C;    Al;    size 100 mum;    voltage 0.31 V;    size 150.0 mum;    organic photovoltaic-based nanophotodiode array;    macula degeneration;    retinal disorders;    retinal prosthesis application;    retinal implants;    retinitis pigmentosa;    subretinal implant;    graphene-based nanophotodiode array device;    NPDA array;    BHJ cell employed photodiode array;    photocurrent density;    NPDA device;    C60 semiconductor layer;    semiconducting single wall carbon nanotube;    graphene alone bottom anode;    bulk heterojunction solar cell technology;    subretinal stimulation;    degenerative retinal diseases;   

DOI  :  10.1049/mnl.2019.0030

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Electrically stimulating the retina of the patients suffering due to extreme retinal disorders such as age related macula degeneration, retinitis pigmentosa is quickly turning into a feasible accomplishment through retinal implants. The objective of this work is to optimise the design, develop and test an organic photovoltaic based Nano Photo Diode Array (NPDA) device for retinal prosthesis application to restoring vision to patients blinded by degenerative retinal diseases. NPDA for subretinal stimulation has been fabricated based on Bulk heterojunction (BHJ) solar cell technology. Each pixel is composed by a graphene alone bottom anode, a semiconducting single wall carbon nanotube (S-SWCNT):C60 blend, and a top cathode in aluminum (Al) of 100 µm or 150 diameter. This NPDA device photovoltaically converts incident light into electric current to stimulate nearby retinal neurons without wired power connections. The fabricated device is able to provide a photo current density of 245 µA/cm 2 and photovoltage of 0.31 V. These results suggest that BHJ cell employed photodiode array used in this work make it better than POLYRETINA and SCNC. The significant improvement in photocurrent density paves the way for scaling up density of NPDA array in implant. Increased number of electrodes will indeed enhance visual acuity to greater extent.

【 授权许可】

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