Smart Contact Lens

A new product (or at least potential product) announcement from Google caught my eye this week – they have developed and are testing prototypes of a smart contact lens that can measure glucose levels in tears. Diabetes is becoming increasingly common, with upwards of 5% of the world’s population afflicted, and managing blood sugar levels is a vital and challenging element of treating the disease. Most patients have to resort to self-administered blood tests via pricking a finger or similar, multiple times per day.

Tears can provide a good barometer of glucose levels in the body, but historically there has not been a good way to access them easily to take measurements. Integration of the sensing technology into a contact lens is an elegant solution to this problem, albeit one with significant technical hurdles to overcome before something like this could become an actual product.

It’s been an eventful few months for Google’s efforts around mechatronics. This announcement followed shortly after they announced they were buying Nest for $3.2B. It’s heartening to see them making both big and small bets on smart technology and I look forward to watching their continued progress.

Pulse of the City

The (legions of) regular readers of this blog have probably noticed some common threads running through at least my posts. One of them is that I’m a sucker for art that provides interesting ways for the audience to interact with the piece, the artist, or each other. Today’s post looks at another really cool project in this vein, this one called Pulse of the City.

Spearheaded by artist George Zisiadis, the project has placed 5 interactive public art installations around Boston. The concept is that passing pedestrians grab the heart-shaped installation and it turns their heartbeat into a unique musical offering, which it plays in real time on embedded speakers. As the creators describe it, “amidst the chaotic rhythms of the city, it helps pedestrians playfully reconnect with the rhythm of their bodies.”

As always, there are some interesting technical elements. Each unit is fully solar powered and has both a Raspberry Pi and an Arduino – my guess is that the Raspberry Pi is responsible for more of the music generation and playing and that the Arduino handles the classical embedded system tasks such as the heart rate sensor and driving LEDs, but documentation is still pending so that’s just a guess at this point. I would also be very curious to learn more about their algorithm for generating the musical compositions each time – that’s definitely an interesting problem and the effort to make the exhibit’s response non-deterministic and unique to each instance really adds to the beauty of the experience for me.

This application is also a great example of some of the engineering challenges that can crop up with interactive art. Measuring heart rate can be kind of a finicky undertaking to begin with and is made more so by the wide range of skin conductivities and signal strengths that can be expected in this context, depending on the individual touching the handles and environmental conditions such as temperature and humidity. Compared to something that only has to function in a more controlled setting, this design illustrates both the headaches required to build a system robust enough to interact with a random passerby and also the reward for doing so – just look at the faces of the people in the video.

Between this and the Color Commons, Boston has seen some really cool interactive public art popping up recently – hopefully some other cities will be inspired and join the trend..

Optical Eavesdropping

Quick, close your eyes! Somebody else may be reading this. Researchers at Saarland University in Germany have shown that it is possible to read the content of a computer screen through reflections present on shiny objects nearby. Teapots, wine glasses, spoons, and even the eyes of the computer user are all reflective surfaces that can support this kind of optical eavesdropping. The research shows that equipment costing less than $1500 can be used to successfully resolve these small reflections from up to 10 meters away, and more expensive equipment can be used from distances over 30 meters. Take a look at the researchers’ findings here.

I am fascinated by this research – in part because I’ve always been interested in spy gadgets, but also because it exposes a disconnect in our sense of security with technology. These days, it is very easy to comprehend digital espionage originating within our computers, because it happens so frequently. However, techniques like those presented by the Saarland University researchers remind us that we are also vulnerable in our own non-digital world. Regardless of how careful we are with passwords and making sure that our computers are free of viruses, our own interaction with technology in the physical world that surrounds us can be used against us.

The good news (and bad news) is that it is far easier to steal your personal information from discarded credit card applications than to take pictures of your computer screen reflected in your eyes. So go ahead, open your eyes and walk over to your shredder with those checks that your credit card company just sent in the mail.

AC vs DC: Edison’s Revenge

Bracket from 1883 Tournament of Genius.

The Original Feud
Though Thomas Edison is remembered as one of the most prolific, influential, and successful inventors in history, he actually lost one of his biggest professional battles.  He spent a large portion of his life wrapped up in a struggle over the future of electricity.  He advocated the use of DC (direct current) power and bitterly opposed champions of AC (alternating current) power such as Nikola Tesla and George Westinghouse.  The “War of Currents” was heated enough that Edison became involved in the development of the electric chair, despite his opposition to capital punishment, to demonstrate what he saw as the dangers of AC power.  He also publicly executed a number of animals via electrocution to prove his point.

In the end, Edison lost; today virtually any wall outlet in the world provides AC power.  However, I think the pendulum may be swinging back and I’m going to float the argument that DC power will enjoy much more widespread use in the next hundred years than in the past hundred.

AC vs. DC Power
It’s actually not quite accurate to imply that DC power has not been used since AC won the power generation and transmission war.  However, it is illustrative to look at the two types of power and their advantages and disadvantages.

DC power uses unidirectional flow of electric charge and is produced by batteries, solar cells, and dynamo-type electric generators.  Generally speaking, it is more difficult to transmit over long distances than AC power without significant energy loss (although high voltage direct current – HVDC – can be used for efficient transmission in certain settings).  Since the adoption of AC power for the electrical grid, the chief use of DC has been in battery-powered applications.

AC power, on the other hand, uses bidirectional flow of electric charge and offers significant advantages over DC for highly efficient power transmission.  Because the power grid is AC, most of the devices in our lives that plug into the wall are designed and optimized for an AC power source (although many of the devices internally convert the power to DC for use).

Centralization vs. Localization
The power grid approach, that has dominated since Edison’s time, uses a combination of large, centralized power plants with a network of transmission and distribution lines to send the power where it needs to go.  AC power is the logical choice in a power grid, because of power transmission advantages. Historically, the economics of power plant design have made a distributed, localized model infeasible.  However, things are now changing.

The Coming Sea Change
Renewable energy generation via technologies such as solar, wind, and hydropower looks to be the way of the future (initially in combination with fossil fuels and eventually exclusively).  In particular, technologies such as solar have a few interesting characteristics: (1) they output DC power and (2) they lend themselves well to a distributed model.  For instance, it’s easy to put solar panels on every roof in a city so that all the buildings are generating power, whereas it doesn’t make sense to have a coal power plant in every home.  In a situation like this, power transmission is not much of an issue since the power is being used in the same place it is being generated.  That being the case, there is no need to convert to AC, send to the wall outlet, and then convert back to DC for use.

Bottom Line
The reason that the today’s electric grid uses AC power (efficient transmission) will matter less and less in a future world where power generation takes place in a more distributed fashion.  Imagine a 12/24VDC world, instead of the 120/240VAC world of today (this brings up a number of questions and issues in its own right, which probably deserve their own post, but we’ll set those aside for now).  The opportunities to both redesign existing appliances and devices and also to create new products that fully take advantage of the new power paradigm are staggering.  So I throw out a challenge to the designers of the world: look around and start thinking about optimizing electrical products for low voltage, DC power – and make Edison proud.

An Igloo in a High-Tech World

An Eskimo can build an igloo in 40 minutes (how to build an igloo). It took three friends and me almost 11 hours to build our first igloo. BUT, the resulting structure and the night of sleep within were very satisfying. On the spectrum of technology, an igloo is much like a wheel: low tech on the whole, but very technical in the details. It is a remarkable structure that is elegant, highly efficient, and can be built using only snow and a saw. However, each block of the igloo must be shaped and placed very carefully if the structure is to support itself.

When we set out into the woods near Lake Tahoe, I brought my mobile phone just in case of an emergency. I tend to do this a lot (“just in case”), but normally there ends up being no phone signal and my phone is dead weight. However, when we arrived at the site of our soon-to-be igloo, I was surprised to see that I had full reception for my phone. With lots of work ahead of us and having no interest in receiving phone calls or emails, I turned off the phone and set it aside. This was no place for technology! We were there to build an igloo!

The next morning, before leaving, we discussed ways to document our little snow dwelling. Beyond the many photographs taken, we decided we should create a blog for the igloo (in hopes that others might find it and update us on its standing). We originally planned to do this once we got back to civilization, but with 3G mobile coverage, we realized that we could do it all from within the igloo! It was quite a technological contrast – using an iPhone to create a blog from within an igloo.

It is this technological contrast that I wish to highlight here. We live in a world of technology, but we also live in a world of igloos. As we get caught up in email, apps (the iGloo app is the next big thing), and digital everything, it is important to remember the simpler, perhaps more elegant, forms of technology that have existed for thousands of years. While the latest technology may be the best thing since sliced bread, sliced bread may just be the best thing since the igloo.

Check out this great book I used for reference and build your own!