Tag Archives: contact lenses

Projecting beams of light from contact lenses courtesy of Princeton University (US)

Princeton University’s 3D printed contact lenses with LED (light-emitting diodes) included are not meant for use by humans or other living beings but they are a flashy demonstration. From a Dec. 10, 2014 news item on phys.org,

As part of a project demonstrating new 3-D printing techniques, Princeton researchers have embedded tiny light-emitting diodes into a standard contact lens, allowing the device to project beams of colored light.

Michael McAlpine, the lead researcher, cautioned that the lens is not designed for actual use—for one, it requires an external power supply. Instead, he said the team created the device to demonstrate the ability to “3-D print” electronics into complex shapes and materials.

“This shows that we can use 3-D printing to create complex electronics including semiconductors,” said McAlpine, an assistant professor of mechanical and aerospace engineering. “We were able to 3-D print an entire device, in this case an LED.”

A Dec. 9, 2014 Princeton University news release by John Sullivan, which originated the news item, describes the 3D lens, the objectives for this project, and an earlier project involving a ‘bionic ear’ in more detail (Note: Links have been removed),

The hard contact lens is made of plastic. The researchers used tiny crystals, called quantum dots, to create the LEDs that generated the colored light. Different size dots can be used to generate various colors.

“We used the quantum dots [also known as nanoparticles] as an ink,” McAlpine said. “We were able to generate two different colors, orange and green.”

The contact lens is also part of an ongoing effort to use 3-D printing to assemble diverse, and often hard-to-combine, materials into functioning devices. In the recent past, a team of Princeton professors including McAlpine created a bionic ear out of living cells with an embedded antenna that could receive radio signals.

Yong Lin Kong, a researcher on both projects, said the bionic ear presented a different type of challenge.

“The main focus of the bionic ear project was to demonstrate the merger of electronics and biological materials,” said Kong, a graduate student in mechanical and aerospace engineering.

Kong, the lead author of the Oct. 31 [2014] article describing the current work in the journal Nano Letters, said that the contact lens project, on the other hand, involved the printing of active electronics using diverse materials. The materials were often mechanically, chemically or thermally incompatible — for example, using heat to shape one material could inadvertently destroy another material in close proximity. The team had to find ways to handle these incompatibilities and also had to develop new methods to print electronics, rather than use the techniques commonly used in the electronics industry.

“For example, it is not trivial to pattern a thin and uniform coating of nanoparticles and polymers without the involvement of conventional microfabrication techniques, yet the thickness and uniformity of the printed films are two of the critical parameters that determine the performance and yield of the printed active device,” Kong said.

To solve these interdisciplinary challenges, the researchers collaborated with Ian Tamargo, who graduated this year with a bachelor’s degree in chemistry; Hyoungsoo Kim, a postdoctoral research associate and fluid dynamics expert in the mechanical and aerospace engineering department; and Barry Rand, an assistant professor of electrical engineering and the Andlinger Center for Energy and the Environment.

McAlpine said that one of 3-D printing’s greatest strengths is its ability to create electronics in complex forms. Unlike traditional electronics manufacturing, which builds circuits in flat assemblies and then stacks them into three dimensions, 3-D printers can create vertical structures as easily as horizontal ones.

“In this case, we had a cube of LEDs,” he said. “Some of the wiring was vertical and some was horizontal.”

To conduct the research, the team built a new type of 3-D printer that McAlpine described as “somewhere between off-the-shelf and really fancy.” Dan Steingart, an assistant professor of mechanical and aerospace engineering and the Andlinger Center, helped design and build the new printer, which McAlpine estimated cost in the neighborhood of $20,000.

McAlpine said that he does not envision 3-D printing replacing traditional manufacturing in electronics any time soon; instead, they are complementary technologies with very different strengths. Traditional manufacturing, which uses lithography to create electronic components, is a fast and efficient way to make multiple copies with a very high reliability. Manufacturers are using 3-D printing, which is slow but easy to change and customize, to create molds and patterns for rapid prototyping.

Prime uses for 3-D printing are situations that demand flexibility and that need to be tailored to a specific use. For example, conventional manufacturing techniques are not practical for medical devices that need to be fit to a patient’s particular shape or devices that require the blending of unusual materials in customized ways.

“Trying to print a cellphone is probably not the way to go,” McAlpine said. “It is customization that gives the power to 3-D printing.”

In this case, the researchers were able to custom 3-D print electronics on a contact lens by first scanning the lens, and feeding the geometric information back into the printer. This allowed for conformal 3-D printing of an LED on the contact lens.

Here’s what the contact lens looks like,

Michael McAlpine, an assistant professor of mechanical and aerospace engineering at Princeton, is leading a research team that uses 3-D printing to create complex electronics devices such as this light-emitting diode printed in a plastic contact lens. (Photos by Frank Wojciechowski)

Michael McAlpine, an assistant professor of mechanical and aerospace engineering at Princeton, is leading a research team that uses 3-D printing to create complex electronics devices such as this light-emitting diode printed in a plastic contact lens. (Photos by Frank Wojciechowski)

Also, here’s a link to and a citation for the research paper,

3D Printed Quantum Dot Light-Emitting Diodes by Yong Lin Kong, Ian A. Tamargo, Hyoungsoo Kim, Blake N. Johnson, Maneesh K. Gupta, Tae-Wook Koh, Huai-An Chin, Daniel A. Steingart, Barry P. Rand, and Michael C. McAlpine. Nano Lett., 2014, 14 (12), pp 7017–7023 DOI: 10.1021/nl5033292 Publication Date (Web): October 31, 2014

Copyright © 2014 American Chemical Society

This paper is behind a paywall.

I’m always a day behind for Dexter Johnson’s postings on the Nanoclast blog (located on the IEEE [institute of Electrical and Electronics Engineers]) so I didn’t see his Dec. 11, 2014 post about these 3Dprinted LED[embedded contact lenses until this morning (Dec. 12, 2014). In any event, I’m excerpting his very nice description of quantum dots,

The LED was made out of the somewhat exotic nanoparticles known as quantum dots. Quantum dots are a nanocrystal that have been fashioned out of semiconductor materials and possess distinct optoelectronic properties, most notably fluorescence, which makes them applicable in this case for the LEDs of the contact lens.

“We used the quantum dots [also known as nanoparticles] as an ink,” McAlpine said. “We were able to generate two different colors, orange and green.”

I encourage you to read Dexter’s post as he provides additional insights based on his long-standing membership within the nanotechnology community.

No need for eye drops when your contact lenses can dispense your eye medication

Anyone who has difficulty getting or allowing drops into their eyes (I once slid out of an ophthalmologist’s examination chair trying to avoid the eye drops he was administering at the end of my appointment) is going appreciate this Dec. 9, 2013 news item on Nanowerk,

For nearly half a century, contact lenses have been proposed as a means of ocular drug delivery that may someday replace eye drops, but achieving controlled drug release has been a significant challenge. Researchers at Massachusetts Eye and Ear/Harvard Medical School Department of Ophthalmology, Boston Children’s Hospital, and the Massachusetts Institute of Technology are one step closer to an eye drop-free reality with the development of a drug-eluting contact lens designed for prolonged delivery of latanoprost, a common drug used for the treatment of glaucoma, the leading cause of irreversible blindness worldwide.

The Dec. 9, 2013 Massachusetts Eye and Ear Infirmary press release (also on EurekAlert), which originated the news item, notes that a lot of people have problems with eye drops and gives a general description of the research,

“In general, eye drops are an inefficient method of drug delivery that has notoriously poor patient adherence. This contact lens design can potentially be used as a treatment for glaucoma and as a platform for other ocular drug delivery applications,” said Joseph Ciolino, M.D, Mass. Eye and Ear cornea specialist and lead author of the paper.

The contacts were designed with materials that are FDA-approved for use on the eye. The latanoprost-eluting contact lenses were created by encapsulating latanoprost-polymer films in commonly used contact lens hydrogel. Their findings are described online and will be in the January 2014 printed issue of Biomaterials.

“The lens we have developed is capable of delivering large amounts of drug at substantially constant rates over weeks to months,” said Professor Daniel Kohane, director of the Laboratory for Biomaterials and Drug Delivery at Boston Children’s Hospital.

In vivo, single contact lenses were able to achieve, for one month, latanoprost concentrations in the aqueous humor that were comparable to those achieved with daily topical latanoprost solution, the current first-line treatment for glaucoma.

The lenses appeared safe in cell culture and animal studies. This is the first contact lens that has been shown to release drugs for this long in animal models.

The newly designed contact lens has a clear central aperture and contains a drug-polymer film in the periphery, which helps to control drug release. The lenses can be made with no refractive power or with the ability to correct the refractive error in near sided or far sided eyes.

Here’s a link to and a citation for the researchers’ published paper,

In vivo performance of a drug-eluting contact lens to treat glaucoma for a month by Joseph B. Ciolino, Cristina F. Stefanescu, Amy E. Ross, Borja Salvador-Culla, Priscila Cortez, Eden M. Ford, Kate A. Wymbs, Sarah L. Sprague, Daniel R. Mascoop, Shireen S. Rudina, Sunia A. Trauger, Fabiano Cade, Daniel S. Kohane. Biomaterials Volume 35, Issue 1, January 2014, Pages 432–439 DOI: S0142961213011150

This article is behind a paywall.

Nano augments reality; PEN’s consumer nano products inventory goes mobile and interactive; Two Cultures; Michael Geller’s ‘Look at Vancouver’ event

There was a nanotechnology mention hidden in a recent article (Augmented Reality is Both a Fad and the Future — Here’s Why by Farhad Manjoo in Fast Company) about a new iPhone application by Yelp, Monocle. From the article,

Babak Parviz, a bio-nanotechnologist at the University of Washington, has been working on augmented-reality contact lenses that would layer computer graphics on everything around us — in other words, we’d have Terminator eyes. “We have a vast amount of data on the Web, but today we see it on a flat screen,” says Michael Zöllner, an augmented-reality researcher at Germany’s Fraunhofer Institute for Computer Graphics Research. “It’s only a small step to see all of it superimposed on our lives.” Much of this sounds like a comic-book version of technology, and indeed, all of this buzz led the research firm Gartner to put AR on its “hype cycle” for emerging technologies — well on its way to the “peak of inflated expectations.”

Manjoo goes on to note that augmented reality is not new although he’s not able to go back to the 1890s as I did in yesterday’s (Nov. 11, 2009) posting about using clouds to display data.

The Project on Emerging Nanotechnologies (PEN) has produced an exciting new iPhone application, findNano which allows users to access PEN’s consumer products inventory via their mobile phones. From the news item on Azonano,

findNano allows users to browse an inventory of more than 1,000 nanotechnology-enabled consumer products, from sporting goods to food products and electronics to toys, using the iPhone and iPod Touch. Using the built-in camera, iPhone users can even submit new nanotech products to be included in future inventory updates.

That bit about users submitting information for their database reminds me of a news item about scientists in the UK setting up a database that can be accessed by mobile phones allowing ordinary citizens to participate in gathering science information (I posted about it here). I wonder how PEN will track participation and if they will produce a report on the results (good and/or bad).

One thing I did notice is that PEN’s consumer products inventory has over 1000 items while the new European inventory I mentioned in my Nov. 10, 2009 posting has 151 items.

I finally finished reading The Two Cultures: and A Second Look (a publication of the text for the original talk along with an updated view) by C. P. Snow. This year is the 50th anniversary. My interest in Snow’s talk was reanimated  by Andrew Maynard’s postings about the anniversary and the talk in his 2020 Science blog. He has three commentaries starting here with a poll, and his May 5, 2009 and May 6, 2009 postings on the topic.

I had heard of The Two Cultures but understood it to be about the culture gap between the sciences and the arts/humanities. This is a profound misunderstanding of Snow’s talk/publication which was more concerned with raising the standard of living and health globally. Snow’s second look was a failed attempt to redress the misunderstanding.

From a writer’s perspective, his problem started with the title which sets the frame for his whole talk. He then opened with a discussion of literary intellectuals and scientists (bringing us back to the number two), their differences and the culture gap that ensues. Finally, over 1/2 of his talk was over by the time he started the serious discussion about extending the benefits of what he termed ‘the scientific revolution’ globally.

It’s an interesting read and some of it (the discussion about education) is still quite timely.

Michael Geller,  local architect, planner, real estate consultant, and developer in Vancouver (Canada), has organized an event to review the happenings in the city since the last election in 2008. From the news release (on Frances Bula’s blog),

SATURDAY NOVEMBER 14, 20009 marks the one year anniversary of the last election day in Vancouver; a day that resulted in a significant change in the political landscape and leadership of our city.  The purpose of this event is to mark this anniversary with a review of the highlights of the past year in Vancouver municipal politics, particularly in terms of the accomplishments of Council and staff in the areas of housing, planning and development; fiscal management and economic development; and leadership.

The event will be held at the Morris J. Wosk Centre for Dialogue (lower level) at 515 West Hastings from 8:00 am to 12:30 pm. Admission by donation. Geller has arranged a pretty interesting lineup for his three panel discussions although one of the commenters on Bula’s blog is highly unimpressed with both the speakers and anyone who might foolishly attend.