Design and development of a self-powered intelligent contact lens with 2D-MoS2 for ocular diagnostics

2022 Fiscal Year Annual Research Report

• Project/Area Number: 22F21367
• Allocation Type: Single-year Grants
• Research Institution: Tokai University
• Principal Investigator: 槌谷 和義 東海大学, 工学部, 教授 (50399086)
• Co-Investigator(Kenkyū-buntansha): JAISWAL JYOTI 東海大学, マイクロ・ナノ研究開発センター, 外国人特別研究員
• Project Period (FY): 2022-09-28 – 2024-03-31
• Keywords: piezoelectric properties / nanosheets / MoS2-PVDF

Outline of Annual Research Achievements

These accomplishments bring us closer to the realization of self-powered intelligent contact lenses with piezoelectric properties, following as; Several achievements were made, including the successful development of a PDMS contact lens fabrication recipe, the fabrication of few-layered MoS2 nanosheets, the development of free-standing few-layered films of pristine-MoS2 and MoS2-PVDF nanosheets, and investigation of their piezoelectric properties. The results showed that MoS2-PVDF nanosheets possess enhanced piezoelectricity compared to pristine-MoS2 nanosheets. Furthermore, transparent conducting polymer PEDOT:PSS thin films were deposited as a contact electrode, with ongoing efforts to improve the coating uniformity. These accomplishments bring us closer to the realization of self-powered intelligent contact lenses with piezoelectric properties.

Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

We have already succeeded in creating PEDOT:PSS thin films on PDMS/PVA coated Si and glass substrates to be used as contact electrodes. Therefore, we are already developing transparent self-powered pressure sensors using MoS2-PVDF nanosheet piezoelectric elements and PEDOT:PSS contact electrodes. Currently, we have started to improve the uniformity of the PEDOT:PSS thin film. In addition, to verify the performance of the pressure sensor: We have begun to test the performance of the developed pressure sensor by measuring the changes in voltage and current when pressure is applied in the range of 8 mmHg (1 kPa) to 30 mmHg (4 kPa), and have partially begun to confirm the repeatability and reproducibility.

Strategy for Future Research Activity

After successfully developing the self-powered pressure sensing devices, the next step is to integrate this sensor into the contact lens and test its sensitivity performance. The first step is to optimize the recipe for embedding the self-powered pressure sensor on the contact lens. Once the optimization process is complete, the next step is to test the sensitivity performance of the contact lens with a mimic eyeball. After testing the contact lens with the mimic eyeball, the repeatability and reproducibility of the self-powered intelligent contact lens will be assessed. Finally, the results of the study will be written up and communicated for publication in an international journal. This will help to disseminate the findings and make them available to other researchers in the field.