Printable Silver Nanowire Touchscreens

Interview conducted by Will SoutterJan 8 2013

In this Insights from Industry interview, John LeMoncheck, President and CEO of Cambrios, tells AZoNano's AZoNano about their novel silver nanowire material for printable touch screens. Touch modules using Cambrios technology will be featured in new products launching this week at CES 2013.

Please tell us a bit about Cambrios and the technology sector you work within.

Cambrios is focused on the transparent conductor materials market. One of the things that we see happening out in the market is this really fast growth of touch. It's becoming ubiquitous, certainly in smartphones and tablets, but now with advent of Windows 8 you can see laptops, ultrabooks and even all-in-one computers that have touch capabilities - devices with a much larger screen area than touch devices we've seen in the past.

You can also now see touch in a wider variety of form factors - Samsung has announced their desire to start developing flexible displays, with flexible touch panels on them, there are e-book readers coming to market that have flexibility, and 3D-shaped devices and so forth.

What does your technology bring to this market, and how does nanotechnology help to achieve this?

The current material that is used in touch panels is indium tin oxide (ITO), which is a really challenging material to work with for a lot of these applications. It is deposited on substrates using chemical vapour deposition (CVD), which requires a vacuum chamber, and can be very expensive for large area substrates. It is a ceramic material, so it's very brittle - if you put it on a flexible substrate it can crack, making it difficult to handle. It is possible to put ITO on films, but that limits the conductivity to around 120Ω/sq because the heat needed to anneal the ITO is so high.

So what Cambrios is focused on is creating a new transparent conductive material that is very easy to deposit, can reach very good conductivities easily, and is also flexible, so it can be used in some of these new applications.

The way we do that is using extremely thin silver nanowires, just tens of nanometers thick, but tens of microns long, so they have an extremely high aspect ratio. They can be suspended in a solution, like an ink, that can be used to coat a wide variety of substrates, like glass, PET, COC, COP - any of the new ultra-thin film transparent substrates.

The nanowires lay across each other randomly, creating a network of wires which forms a conductive surface on top of the substrate. This network, however, is mostly space, because of the thinness of the wires. This makes the surface transparent - you can literally see right through it - and yet still highly conductive because it is made out of silver.

Because this is a solution-based process, we can coat these substrates very quickly, using any of the standard roll-to-roll printing techniques, just like printing a newspaper. This reduces not only the materials cost, but also the manufacturing cost of putting a transparent conductor on a substrate.

LG's touchscreen products at CES 2013, including the AIO V325 - featuring Cambrios ClearOhm™ Technology. Image credit: LG/Flickr.

What made you originally decide to work in this area?

The company was founded on some research work in nanotechnology which came out of MIT and the University of California. The work was based around how to construct inorganic chains of molecules using organic processes. Putting together silver nanowires using this very basic technology was one of the most interesting uses that came out of this work. When looking at different potential applications, the growth of touch in particular seemed like it was ripe for a replacement to ITO, and that is what led to our focus on that area.

Whilst touch is the first market that Cambrios is focusing on, transparent conductors are used all over the place, in displays as electrodes, in photovoltaic cells, OLED lighting tiles, electrochromic windows, and so on.

As startups have to, we had too focus on one application area to begin with, but we really see our ability to expand into these other markets. That was something which attracted us to transparent conductors in the first place - this opportunity for a range of applications across a number of different market segments.

Some products containing your technology are being showcased at CES this week - can you tell us a little about these new products?

We have spent the last few years developing this material, and developing partnerships within the industry. The kinds of devices we are working with have quite a complex supply chain, as you might imagine - we sell coating solutions to companies such as Toray, Okura, DIC, etc. They then create the film and sell that to the touch module manufacturers, who put them together with the necessary chips, and laminate the films to the cover glass, and finally that module goes into a device.

Recently, simultaneously with the launch of Winwos 8 in October 2012, we announced that LG had launched the first large-area touch device using our material, an all-in-one computer (the AIO V325), and at CES this week we are announcing a number of other new products with a few of our partners.

One of these partners is GVision, a company that supplies industrial touch monitors - they are launching some products with our material at CES. We really enjoy working with them, because they have shown that our material can stand up not only to the rigours of a consumer electronics products, but also to the much more stringent requirements of an industrial monitor, which really shows off the reliability of the material.

We are also announcing some new partnerships in the supply chain - eTurboTouch is a supplier of large-area touch modules to this ecosystem. They have announced their new large touch module, available in sizes up to 23", which is based on our material and will be shown at our suite at CES. Also, CNi, another company in the touch sensor/touch module manufacturing business, are showing some large area touch modules designed for ultrabooks, in the 13" size range. They have some unique laser patterning capability, so that they can make really fine lines and invisible patterns using our material.
LG has now gone beyond the all-in-one computer product, and will be showing two new touchscreen monitors in their booth at CES using our material. These products are designed to offer an upgrade path for users who want to switch to Windows 8 and get the most out of the touch capabilities of the operating system, without needing to upgrade their whole computer - the monitors can be added to any laptop or desktop to add that touch capability.

So we are really excited about the growth of this material in the market, and we should have a number of other product announcements throughout the rest of 2013.

How big a role has Cambrios played in the development of these products?

One of the things about bringing a new material to market is that you really have to teach the whole supply chain how to use it.

Until just last year, Cambrios actually sold our own coated film, in order to convince the market that you really could make a transparent conductive film with our technology. We used a contracted coating company to put our material on the substrate, and did all the reliability testing, figured out etching techniques for patterning the material, worked on lamination techniques so you can attach it to cover glass or to the LCD directly, and really had to understand how to build a complete touch sensor, in order to show all the layers of the supply chain that this was viable.

Last year, there was a phone launched in Japan that used that film from Cambrios directly, but now that we have shown people how viable this is, we have gone back to the business model we originally planned, which was just to supply ink to manufacturers - there are plenty of companies out there that are excellent at coating things, and there is no need for us to compete with them.

We still get really involved at every level of the supply chain, teaching people how best to use the material effectively, showing touch module manufacturers how to pattern the surface, and how to attach the silver paste busbars, etc.

We have a strong partnership with Synaptics, who are a major touch IC manufacturer, to make sure that their ICs work effectively with our material. We remain quite involved with all the technical aspects, all the way up to the finished product. In fact, our relationship with LG demonstrates how we work with even the end OEM, who are making the device that will incorporate this touch module, to make sure that there are no issues when they integrate it into their final device.

How long will it be before these products are available to consumers?

You can buy them today! There are phones on the market in Japan as we speak, the LG all-in-one that I mentioned is available in Japan and Korea at the moment, and will be going to other geographies shortly. The new LG touch monitors launching at CES this week should be available very shortly as well.

How did your relationship with LG begin?

We work with a division of LG Electronics called CEM (Chemical & Electronic Material), which is their chemical and materials business. They were looking to enter the touch market, and were looking for an advantage, as they were a new entrant into the touch module manufacturing market. They felt that our material would give them that advantage.

We've been working with them for several years now, helping to develop the processes, helping to work out all of the manufacturing lines and so forth. It's been a terrific partnership, and we're very excited about it.

We do work with a broad variety of partners as well - our partnership with LG has been particularly productive recently, but we also announced a significant investment in Cambrios last year from Samsung, so we have a very strong relationship with them also.

We have also announced many other partnerships up and down the supply chain including Toray, ShinEtsu, DIC, Okura, and Nissha. These companies supply value added films, touch modules, or both to the market, and we have significantly expanded our ecosystem in this regard lately.

What aspects of nanotechnology are the most crucial to the performance and viability of these products?

With this type of material, there is always a tradeoff between optical transmission and conductivity. This is a constant challenge, and it stems from the fact that the idea of a transparent conductor is basically at odds with physics - transparent materials have that property because their electrons can't move around very much, which typically makes them excellent electrical insulators.

One of the things that we pride ourselves on is having significantly better transmission for a given conductivity than ITO. But possibly the more important thing is the manufacturing processes that you can use our ink with. Rather than having to deal with expensive vapour deposition, you can just print this material.

Typically our customers roll-to-roll coat blanket sheets of film, then pattern and etch the surface to create the touch module, because that is exactly the way that the module manufacturers are used to dealing with ITO. We wanted to enter the market with that capability to behave exactly like ITO in the manufacturing environment, to make the adoption of our material as simple and as cheap as possible.

But in fact there is no reason why you couldn't just print the material, to deposit and pattern in one single step, with no tradeoff in optical or electrical performance. That is something that ITO will never be able to do, and that's going to be the next step of manufacturing optimization that our close partners will be working on over the next year or so.

What challenges have you encountered with nanomanufacturing on a large scale? How did you overcome them?

There are certainly a lot of challenges there. Going from making 100ml of something to 100 litres of something is a very big step. That is why Cambrios has been around for 8 years now, perfecting those processes, making sure we can scale them efficiently, and that we are not good at just making the nanowires, but also that the solutions we provide them in contain all the necessary additives you need to stop the nanowires agglomerating, and so that they coat smoothly and evenly across the surface. There is a lot of know-how in there which has taken years to develop, but we are there now.

We manufacture here in the USA, in Sunnyvale, California, and it's a very efficient manufacturing line. When running at full capacity we can create enough ink to coat tens of millions of square meters of material, enough to cover all the iPads on the planet.

So we have now overcome that manufacturing hurdle, although it wasn't easy. Actually one of the biggest questions we get from customers is whether we can deal with the scale, but once they see our manufacturing line and the scale of our reactors, they always leave satisfied that we can fulfill their needs, in terms of the volumes that they want to move.

How do you see the role of nanotechnology increasing in the consumer sphere over the next few years?

Small, thinner, and more power efficient is where everything wants to go. I think that there is only so far you can go in that direction with the current set of materials that are out there. Even on the semiconductor side, Moore's Law is starting to run out of steam, and that industry is starting to turn to materials aside from silicon.

I think materials innovation at the nanoscale is where the next set of really big industry-changing innovations are going to happen. We see this with some of the printed electronics that are coming out, our material in the transparent conductor market, new forms of FETs that are starting to be created on the semiconductor side, graphene and carbon nanotubes, etc. There is a whole host of materials out there that are showing quite a bit of promise for overcoming the huge challenges in making some of the traditional stuff smaller.

I do think that we are on the cusp of big changes in the way that multiple industries do these things, and it's fun being part of that, and creating not just the technology but also the manufacturing capability to serve a real market, taking these materials out of the lab and onto the shelf.

Applications for touchscreens and flexible displays have been held back by the lack of a suitable transparent conductor - Cambrios ClearOhm™ technology fills this gap, opening up a world of new touch devices.

Are there any future developments in the industry that you are looking forward to seeing come to fruition?

I am intrigued by the flexibility that our material can enable. Screens and touch panels thus far have been big, flat, rigid things, and I think that is about to change. For example, manufacturers will be able to put our silver nanowires around 3D shapes, to create kiosks or car dashboards or any number of objects that are covered in touch capability, and are reprogramable and repurposable. Foldable displays, so that you have something the size of a cellphone that unfolds or unrolls into a full-size tablet, will also become possible. I think there is a big set of innovations in industrial design that are going to be enabled by flexibility in touchscreens. Even if the final device is not flexible, being able to create touch sensors that roll over the edges of 3D objects will lead to some real innovations with respect to form factor.

In addition, looking at other markets, the printability that I've talked about could be applied to, for example, making photovoltaic cells cost-effective at a very large area, or spurring growth in the OLED lighting market, replacing fluorescent bulbs in ceiling fittings with beautiful lighting tiles. The cost-effectiveness that we can bring to the manufacturing process could really enable these industries to do things that they simply have not been able to do yet.

What are Cambrios' plans for the near future?

As a small company, as I mentioned, you need to have a really tight focus in order to get started. For 2013 we will remain focused on the touch market, we are very excited about the developments in this area, particularly with Windows 8, and we are looking forward to watching how touch will penetrate into notebooks and larger-area devices.

These other initiatives I have mentioned take several years to percolate, but in fact we have already started on some of them. Heliatek, for example, one of the leaders in OPV in Germany, has already announced working with us on roll-to-roll printing of PV cells. We have some nice results from some OLED work as well. whilst these are longer term projects, we are already actively doing development work in these other areas, and we will probably see them start to generate real products in the next 2-3 years.

Where can we find more information about Cambrios?

We will be rolling out an update to our website this week, and all of the information about the products and our technology are up there, along with all our recent press releases. You can also get in touch with us on Twitter, and check out our YouTube channel.

About John LeMoncheck

John LeMoncheck is a distinguished leader of both startups and public companies. Prior to Cambrios, LeMoncheck was president and CEO at SiBEAM, a leader in millimeter wave solutions and developer of high-speed wireless communications technology. Under LeMoncheck’s leadership, the company successfully shipped WirelessHD products to the consumer electronics and PC markets and was acquired by Silicon Image in 2011.

Before joining SiBEAM, LeMoncheck was vice president of Consumer Electronics and PC/Display Products for Silicon Image, where he led the company's successful launch and commercialization of the HDMI standard. An industry veteran, LeMoncheck held executive roles at various technology companies including TeraLogic, subsequently purchased by Zoran and now owned by CSR, Arithmos, Inc., which was successfully acquired by STMicroelectronics and was also a member of technical staff at Synaptics.

He has a bachelor's of science degree in Electrical Engineering from U.C. San Diego and spent several years researching VLSI for imaging and pattern recognition applications at Caltech.