Imec, Ghent University and SEED demonstrate electronics in hydrogel-based soft lenses

LEUVEN (Belgium), November 19, 2018 — At the imec technology forum Japan (ITF Japan 2018), imec, the world-leading research and innovation hub in nanoelectronics and digital technologies, the Ghent University (UGent), and contact lens manufacturer SEED Co., Ltd. announced that they have developed a contact lens with an integrated LED light, including an ultra-thin silicon microchip, radio‐frequency (RF) antenna for wireless energy transfer, and stretchable thin‐film interconnections. Different from the traditional contact lens-type wearable devices made of non-water-containing material, this novel device is made of hydrogel-based material. This demonstration of autonomous electronics in hydrogel-based soft lenses opens the door to unique applications such as lenses with sensors and/or drug-delivery systems for the treatment of different eye disorders, at the congenital, post-surgery or trauma level. The main advantages of such devices are their low invasiveness level and continuous monitoring in an almost imperceptible manner.

About 130 million people worldwide wear contact lenses, mainly to correct their vision. Now, with electronic systems getting ever smaller and with the possibility of having electrical power on-lens, it becomes feasible to integrate a variety of transducers (i.e. physical, biochemical, etc.) into a lens. This is interesting for diagnosing and treating ocular diseases. The challenge is to integrate a complete autonomous system and make it as flexible as a soft lens, without compromising its oxygen-permeable nature and the integrity of the electronics components.

CMST, an imec research group at Ghent University, together with SEED Co., Ltd., demonstrated a semi-passive smart lens with blue LED light powered by an RF coupling. Besides power transfer, the RF link can be used to calibrate the integrated transducers and reading the sensors out into a handheld device for further post-processing. The spherical‐shaped electronics were made by imec/CMST, whereas SEED Co., Ltd. was responsible for the seamless integration into the hydrogel-based soft lens. The interconnect substrate is based on thermoplastic polyurethane (TPU), a material with a low glass transition temperature, relatively low hardness, proven biocompatibility, optical transparency, conformal fitting, oxygen permeability, and flexibility comparable with soft contact lenses (e.g., hydrogel‐based). Moreover, the viscoelastic nature of TPU allows planar structures to be thermoformed into spherical caps with a well‐defined curvature (i.e., eye's curvature at the cornea: 9 mm). Very precise fine‐tuning of the thermoforming parameters and optimization of strain‐release patterns enabled to achieve oxygen permeable, thin, non-developable, and wrinkle‐free contact lenses with integrated electronics. Well chosen gaps in the circuit provide for oxygen permeability of the lens.

“Flexible and stretchable electronics hold a lot of promise for medical applications,” explains Andrés Vásquez Quintero, imec researcher and professor at UGent. “They can be integrated in intelligent clothing, and even – when combined with highly miniaturized electronics – in smaller devices such as contact lenses. Major challenges have to be overcome to make a truly autonomous smart lens which is comfortable to wear and stable for a few days or even weeks. The integration of a LED light in a semi-passive RF wireless platform is the first important step towards a device that will change the life of many.”

Following steps will focus on developing active lenses with extended power autonomy in order to drive and readout the integrated transducers and on the design of micro-transducers compatible with stretchable systems similar to the one presented here.

“With this technology, contact lens-type wearable devices could be mass produced as those existing contact lens products.” States Ms. Arai, researcher at SEED Co., Ltd., one of the developers of the device. “Moreover, the device could be installed on the outer side (tear film side), the inner side (cornea side), or in the center part of the contact lens. The adjustability of location is valuable for the biosensing field. Also, the possibility of mass production indicating the possibility of disposability, which makes the contact lens-type wearable devices more approachable to the patients around the world, and should contribute to their quality of life.”

From now on, the R&D group is dedicating to the development of contact lens material for biological monitoring. 

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Hanne Degans
press communications manager - imec

About imec

Imec is the world-leading research and innovation hub in nanoelectronics and digital technologies. The combination of our widely acclaimed leadership in microchip technology and profound software and ICT expertise is what makes us unique. By leveraging our world-class infrastructure and local and global ecosystem of partners across a multitude of industries, we create groundbreaking innovation in application domains such as healthcare, smart cities and mobility, logistics and manufacturing, energy and education.

As a trusted partner for companies, start-ups and universities we bring together more than 4,000 brilliant minds from over 85 nationalities. Imec is headquartered in Leuven, Belgium and has distributed R&D groups at a number of Flemish universities, in the Netherlands, Taiwan, USA, China, and offices in India and Japan. In 2017, imec's revenue (P&L) totaled 546 million euro. Further information on imec can be found at

Imec is a registered trademark for the activities of IMEC International (a legal entity set up under Belgian law as a "stichting van openbaar nut”), imec Belgium (IMEC vzw supported by the Flemish Government), imec the Netherlands (Stichting IMEC Nederland, part of Holst Centre which is supported by the Dutch Government), imec Taiwan (IMEC Taiwan Co.) and imec China (IMEC Microelectronics (Shanghai) Co. Ltd.) and imec India (Imec India Private Limited), imec Florida (IMEC USA nanoelectronics design center).

About SEED

SEED is a TSE listed comprehensive contact lens manufacturer in Japan with 60 years history. SEED produces and delivers a wide range of contact lens products including RGP lenses, soft conventional lenses and a number of disposable contact lenses. Its production capacity of daily disposable contact lens is currently 44million pieces per month in its factory located in Japan.

SEED is keen to expanding internationally in the next decade. Currently SEED has direct subsidiaries and/or Rep offices in: Shanghai, China; Taipei City, Taiwan; Kuala Lumpur, Malaysia; Hanoi, Vietnam; and Singapore. In this year SEED has also established its new European subsidiary near Hamburg in Germany, to conduct regional distribution in Europe, and in Louvain-la-Neuve in Belgium, to conduct research into new materials in Europe. In addition, SEED exports its products to 24 countries and regions.

About Ghent University

Ghent University is one of the major universities in the Dutch-speaking region of Europe. It distinguishes itself as a socially committed and pluralistic university in a broad international perspective. About 80 faculty departments, spread over 11 faculties, offer high-quality courses in every one of their scientific disciplines.

Next to this, Ghent University strategically invests in multidisciplinary clusters to expand its industrial R&D network. Key technology transfer activities include industrial collaboration programs, IP licensing and spin-off creation. Over the past ten years, this joint effort has resulted in 439 granted patents, the establishment of 68 spin-off companies and an intensive collaboration with companies.

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