By Sanjena Venkatesh ‘21
Figure 1: In the first step towards developing an artificial eye, University of Minnesota researchers 3D printed an array photoreceptors onto a hemispherical surface (Image Source: Wikimedia Commons)
Over the past few weeks, discourse surrounding 3D printing technology has been limited to the controversy of 3D-printed guns. However, perhaps unknown to many, a team of researchers at the University of Minnesota has for the first time successfully printed a 3D image-sensing array onto a curved surface, taking a tremendous step towards the creation of an artificial, or ‘bionic’, eye prototype (4). This device, though seemingly futuristic, has the potential to someday cure blindness and other forms of visual impairment.
Across the world, approximately 253 million individuals live with either blindness or a moderate to severe form of vision impairment (4). Its causes can be attributed to a variety of factors, from un-operated cataracts and un-corrected refractive errors, to glaucoma (4). Furthermore, the estimated number of individuals affected by common eye diseases is projected to double by 2050 (3). As such, this so-called “bionic” eye could revolutionize optoelectronics.
The research team, led by Professor Michael McAlpine, faced several obstacles. Perhaps the most significant of these was the challenge of printing electronics onto a hemisphere. To overcome this difficulty, they chose to use a silver-particle based ink. When dispensed, this ink did not run down the sides of the printing surface; rather, it remained place and dried evenly (4). Then, using semiconducting polymers, the researchers printed photodiodes, achieving a 25.3% efficiency in the conversion of light to electricity (2). Such results, though achieved solely through the use of a multi-material 3D printer, rivaled those of devices created in conventional microfabrication facilities.
These 3D-printed photodectors though, are still in their primitive stages. Future studies will aim to improve “image-sensing resolution” by scaling down the device as well as to implement additional customizable features, such as an optical sensor that monitors vitals (2). While we may still be far from the sci-fi-esque “bionic eye”, this success story certainly proves the potential for 3D printing to play a significant role in the realm of optoelectronics.
References:
- Blindness and Visual Impairment. (2017, October 11). World Health Organization. Retrieved from http://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment.
- Park, S. H., Su, R., Jeong, J., Guo, S., Qiu, K., Joung, D., Meng, F., McAlpine, M. C. (2018, August 28). 3D Printed Polymer Photodetectors. Advanced Materials. Retrieved from https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201803980
- Statistics and Data (2018, July). National Eye Institute. Retrieved from https://nei.nih.gov/eyedata
- University of Minnesota. (2018, August 28). Researchers 3D print prototype for ‘bionic eye’. ScienceDaily. Retrieved September 16, 2018 from sciencedaily.com/releases/2018/08/180828172043.htm