Touch project PhD researcher Kjetil Nordby has just published two journal articles on interactions with RFID and NFC. These articles pull together concepts from ubiquitous computing and HCI, integrated with high-level interaction design practice, alongside analysis from activity theory, and come up with novel theories for the field of design research.
“Multi-field inputs are techniques driven by multiple short-range RFID-enabled artifacts like RFID-tags and RFID-tag readers. The technology is useful for designers so as to enable the construction of advanced interaction through the physical world. To take advantage of such opportunities, it is important to understand the technology in terms of what interactions it might offer designers. I address this issue by unwrapping and exposing elements that can be used to conceptualize multi-field interactions. This is done by way of a design driven inquiry in which design and research methods are used to investigate short-range RFID technology. My approach is informed by activity theory which I use to analyze RFID technology from a design perspective. The study presents multi-field relations as a conceptual framework that can be used to describe and generate multi-field inputs. Four types of multi-field relations are discussed: one-way, two-way, sequence and multiple relations. These are described and analyzed in context of a set of multi-field input examples. The multi-field relations expose elements that can be used to construct interactions. This is important for interaction designers, since new interactions presents designers with opportunities for making entirely new types of interfaces that can lead to interesting and surprising experiences.”
“Short-Range Radio Frequency Identification (RFID) is an emerging technology that interaction designers are currently embracing. There are, however, few systematic efforts to utilize the technology as a tool for the development of new design concepts. This article focuses on technology as a design material and its role in the formative process of conceptual design. My approach involves the use of activity theory and the concept of motives, used to analyze short-range RFID technology when considering the field of design. I employ practice-based research where qualitative design and research methods are used to scrutinize the use of this technology in design. A design material perspective frames the short-range RFID technology as a composite consisting of near-fields and the computational. This material is coined near-field material and is further described through six form-making qualities: Tap and Hold, Multi-Field Relations, Multi-Field Distribution, Field Shape, Context Sharing and Mediation Type. I propose that the near-field material and thus the six form-making qualities cited above, offer designers engaged in creating user-oriented experiences, a morphology of form types. I argue that by synthesizing and analyzing emerging technology in relation to designers’ motives for using them, we may further support research and practice by placing technology inside design discourse and culture.”
We’ve compiled a short sequence of some of the design experiments and tests in audiovisual media in the Touch project. Here we show some of the ‘behind the scenes’ tests and processes where we used cinematic/video/filmmaking tools as a means to uncover potentials and constraints around an emerging technology.
In these experiments we designed and invented spaces, objects, movements and audiovisual techniques that map and visualise the interactive phenomena of RFID. Many of the visual/cinematic concepts for Nearness and Immaterials were invented by exploring and experimenting with film.
Rather than investing time in creating complex software and hardware prototypes, the interactive experience can be quickly explored inside film compositing applications. These experiments have shown us that there is great value in having tools that offer efficient prototyping of interactions at an experiential level, that don’t need to rely on complex electronics or physical design. There is also value in working within a medium that is not tied to a specific location or a unique demonstrator, and that is editable, reproducible and transmissible allowing it to be shared freely and widely amongst a research group and across the internet.
This is the subject of a forthcoming paper that we’ll flag up here as soon as it is published.
These are some of his lovely experimental renderings of a three dimensional interpretation of the RFID symbol that we developed from the immaterials visualisations.
We are beginning to see RFID and NFC peripherals beginning to be released for the iPhone. Since our conceptual video prototype of the iPhone object-based media came out in April, we’ve had thousands of emails requesting details about such a peripheral. Here is the first, the iCarte.
“The iCarteTM is a Near Field Communication (NFC) / Radio Frequency Identification (RFID) Reader, designed to provide NFC two-way communication, RFID read/write and contactless payment capability for the iPhone. NFC and RFID tag information can be written and read by the iCarteTM and communicated to the iPhone or to any Computer with a USB port. iCarteTM has an embedded smart-chip that can be configured as debit, credit, pre-paid and loyalty cards, for secure contactless transactions. iCarteTM can also read NFC Smart Posters, download or upload electronic coupons, tickets or receipts. iCarteTM is ideal for iPhone users who want to use their iPhones for fast and secure contactless payments, transit payments, loyalty rewards, checking balances, top-up, discovering new services from smart posters or kiosks and exchanging information with other NFC phones. Business iPhone users can use the iCarteTM for commercial applications such as asset tracking, document tracking, healthcare, security and access control.”
I’ve also heard rumours that Core RFID is about to have a reader available for the iPhone, and we’ll flag that up here as soon as we hear anything more.
One of the first long-exposure photographs that proved the mapping technique.
Adam Greenfield uses the work to reflect on how design decisions about seemingly small details—such as the range of an RFID reader—can have significant implications for wider systems and infrastructures:
“Rather than asserting “an RFID” as some eternal given, something that will produce the same linear, determinate effect each and every time it is deployed, Immaterials reminds us that the choice of material, shape, size, direction, orientation and power rating of the components involved have distinct consequences for the uses to which those components can be put. And as we’ve seen, these choices can produce effects on levels seemingly entirely removed from the interaction itself.”
Dan Hill goes back to the ‘invisibility’ of electricity and relates the work to his own experiments looking at the immaterial aspects of the city:
“In their work I even see something of the early experiments of, say, Benjamin Franklin and Nikola Tesla in terms of understanding the behaviour of electricity, such that it can then be tamed, conducted, and put to work. It’s perhaps drawing a long bow to make that comparison, but it feels like a similar sentiment. Whilst electricity is hardly invisible, there is a sense of trying to understand such immaterial phenomena through prototyping and experimentation. ”
Here in the discussion Mitchell Whitelaw responds to what he sees as the false opposition between material and immaterial, suggesting transmaterial as a suitable alternative term for the new kinds of materials that we are working with. Have a look at Mitchell’s weblog for more on the term transmaterial and ‘expanded computing’.
The technically focused audience at Slashdot questioned the reasons for doing such a study. A common criticism here is that manufacturers data sheets and computer simulations should be able to give us a quicker and more accurate model of the interaction:
“For a theoretical/measured depiction they could just read the reader manufacturer’s data sheet, which will almost certainly contain a diagram of the antenna sensitivity pattern in a couple of planes and probably some concrete figures.”
“The subtlety seems to be that they’re not plotting an RF field, they’re plotting the volume in which the passive tag will respond to an RF field (of a given strength). It’s another level of abstraction. Yes, once somebody has come up with the idea then the implementation looks simple enough, but the idea is quite remarkable.”
“The main reason they did this is to map out the field interaction between the RFID tag and the reader, which is not a trivial thing to visualize based on the two data sheets.”
Also discussed here was a technical point that raises wider concerns about privacy, security and eavesdropping:
“Remember, anything radio is not theoretically limited in range. Only practical implementations have set limits. ”
“Yes, but RFID passive responses very quickly go below ambient background noise, in effect limiting even the theoretical range to 1-2 m for all but most exotic radio-noise free environments.”
This discussion shows that—even though we are keen for these images to be used as material in the discussion of privacy and the problem of invisibility—the physical limitations for snooping or eavesdropping are more complex. And if we then take RFID systems as a whole, there are far wider concerns that are much broader than physical/spatial relationships such as the long-term storage of data on travelcard or passport usage for instance.
A glimpse behind the scenes of the Immaterials filmmaking.
We received lots of emails and comments from specialists involved in radio and antenna design, who saw the visualisations as empirical evidence:
From Paul B. via email:
“I’ve worked in both passive and active RFID for about 15 years and want to congratulate you on the very effective and entertaining visualizations. I’ve done my share of winding coils, blinking LEDs and have created diagrams mapping fields so I know how hard it is to make something that is useful and actually helps non-tech people understand the weird world of RFID.”
From Dave H. via email:
“We have had to use huge anechoic chambers with massive parabolic reflectors and extremely stable transmitters to measure the field strength pattern of antennae. I know it’s a world away from that sort of large scale tech but your RFID visualisations blew me away. It’s fantastic. A brilliant idea. And it works perfectly.”
And finally some kind words from both Fast Company:
“As technology progresses, we need better symbols to understand all the gadgets and electrical hubbub that surrounds us. What could be better than symbols that actually reveal a bit about how a technology works?”
“Rarely does one have the opportunity to watch a discourse take large strides, but I get the feeling that’s exactly what we’re witnessing as Touch/BERG elaborate nearfield communications as something with nuance – in other words, as a material.”
This video is about exploring the spatial qualities of RFID, visualised through an RFID probe, long exposure photography and animation. It features Timo Arnall of the Touch project and Jack Schulze of BERG.
The problem and opportunity of invisibility
RFID is still badly understood as an interactive technology. Many aspects of RFID interaction are fundamentally invisible; as users we experience two objects communicating through the ‘magic’ of radio waves. This invisibility is also key to the controversial aspects of RFID technology; once RFID antennas are hidden inside products or in environments, they can be invoked or initiated without explicit knowledge or permission. (See here for more on the invisibility of radio.)
But invisibility also offers opportunities: the lack of touch is an enormous usability and efficiency leap for many systems we interact with everyday (hence the success of Oyster, Suica and Octopus cards). But there is also the ‘magic’ of nearness one of the most compelling experiential aspects of RFID.
As designers we took this invisibility as a challenge. We needed to know more about the way that RFID technology inhabits space so that we could better understand the kinds of interactions that can be built with it and the ways it can be used effectively and playfully inside physical products.
The experiments
In order to study the readable volume around an RFID reader, we built experimental probes that would flash an LED light when they successfully read an RFID tag. The readable volume is not the same as the radio field, instead it shows the space within the field in which an RFID tag and an RFID reader will interact with each other.
One version of our probe containing a tag and LED light connected to the RFID reader that is being studied.
In a dark room, the probes were moved around the various RFID tags and readers that we wanted to study, with a camera taking long-exposure photographs of the resulting patterns of light. In this way we could build up layers by slicing through the field in different ways, creating animations that clearly reveal the spatial properties of this interaction.
These experiments were carried out in order to help us flesh out our own models of the technology, and were not intended to be scientifically accurate. So although they accurately reflect the behaviour of the technologies in the situations that we work with, there were no controlled environments or settings for generalisable technical accuracy.
Innovations ID 20
The Innovations ID 20 RFID reader has become one of the standard components in a lot of our work, it is small, robust and relatively cheap. So it has been very important for us to gain an understanding of the readable volume it produces when we embed the reader inside products such as Sniff and Skål.
The resulting visualisation shows the way in which we have mapped the boundary of the readable volume, although a tag will read anywhere inside this, we have only mapped the edge for the sake of clarity. From the animation (see the video) we start to clearly see that the readable volume is made up of a strong central sphere, accompanied by a smaller lobe that surrounds the edge of the reader.
Oyster card
Mifare cards are one of the largest public applications of RFID, used in many transit systems around the world such as the Oyster and Suica cards. It has become common to have to touch in and touch out of subway stations, and many people have become accustomed to this interaction. So what does the readable volume around an Oyster card look like?
Details: Standard Mifare Oyster card, probed with a Sonmicro high-frequency reader.
With a square antenna inside the Oyster and the Sonmicro reader, we get an elongated main volume, accompanied by long skinny lobes on each edge of the card. This looks very different from the ID 20 mapping.
Orientation
The first two mappings held the reader and the tag parallel to each other, but we predicted that there would be a higher degree of complexity in the relationship if the tag and the reader moved in different orientations. The rig below was built so that we could control the angle between the reader and the tag, which moved along the surface of the table.
There is clearly enormous physical complexity in this relationship, in the animation we can see the volume growing and shrinking, lobes turning into spheres, and vice-versa. But the animation gives us a very clear picture of the ‘throw’ of the reader onto a single two-dimensional plane, almost like looking at it as a torch.
Parallel and perpendicular
To show the two extremes of the relationship between orientation and the readable volume, we created two mappings, one with the tag parallel to the reader, and the other with the tag perpendicular. We mapped them using two different colours of LED: green for parallel and red for perpendicular.
This image is a composite of the two mappings (see the video for animations of the two mappings separately) and it is clear that the readable volume is significantly different. When the tag is perpendicular to the reader, there is a sizeable gap in the middle of the reader where the tag will not read, creating two readable volumes side by side.
Conclusions
We have been continually challenging the ways in which RFID technology has been framed. It is incredible how often RFID is seen as a long-range ‘detector’ or how little relevant information is contained in technical data-sheets. When this information is the primary material that we are working with as designers, this is highly problematic. By doing these kind of experiments we can re-frame the technology according to our experience of it, and generate our own material knowledge.
One of the early motivations in this project was the way in which the animations really captured our tacit, embodied knowledge of the readable volume in a visual way, it was almost as if you could wave your hand through the floating green LEDs and feel them. Of course we had felt it hundreds of times in experimenting with tags and readers, but we had never seen it captured in an image, in a way that was communicable to others without having them try an interactive demonstrator. With this visual material, we can communicate about RFID in ways that we couldn’t previously.
So we hope that this work goes some way towards building better spatial and gestural models of RFID, as material for designers to build better products and to take full advantage of the various ways in which spatial proximity can be used. And with this better understanding we hope to be able to discuss and design for privacy and the ‘leakage’ of data in a more rigorous way.
The project was made by Timo Arnall and Einar Sneve Martinussen from AHO and Jack Schulze from BERG. Thanks to Jørn Knutsen for help in building the rigs.
Touch is a research project that investigates Near Field Communication (NFC), a technology that enables connections between mobile phones and physical things. We are developing applications and services that enable people to interact with everyday objects and situations through their mobile devices. More...
