Haptic Visions. Valerie Hanson
y, and z directions that intensifies multi-directional interaction dynamics also affords researchers opportunities to manipulate individual atoms. For example, in another experiment, researchers J. G. Kushmerick et al. moved a nickel atom in order to observe how far (and how) atoms hop from place to place (2983). However, until Eigler and Schweizer published the article in Nature with the “IBM” images, researchers had not announced the manipulation of atoms by actually picking them up, “dragging” them, and repositioning them—a practice that the ability to move in x, y and z directions made possible. Although large-scale or automated manipulation of individual atoms is not a common use of the STM, even as I write this, manipulation of the surface becomes almost encouraged due to the dynamics created by the microscope’s data-gathering process.
The coordinated x, y, and z directions also structure possible interactions between user and atoms through the arrangement of atomic interactions. The focus on measuring a series of interactions—and the ability to intervene, to change the interactions without destroying the sample—all encourage users to participate in the data-gathering process, as the measuring process becomes part of the experiment. The STM, then, is both a data-gathering probe and an experimental probe—and also an image processor, as explained in the next section.
GUI Image Processing Dynamics
The data produced through coordinated tunneling, rastering, and z-direction interactions is arranged in a matrix to create an image of atomic phenomena. Following the general process of scientific visualization, the raw data is arranged and thus transformed into images that viewers can interpret (see, for example, Brodbeck, Mazza, and Lalanne 30–31). The computer makes image creation relatively easy; however, despite the fact that Binnig and Rohrer worked for IBM when they developed the STM, they did not use computers to develop or operate the first STMs. Instead, Binnig and Rohrer created the first STM images by mentally building up atomic visions using an oscilloscope monitor’s two-dimensional trails of the tip’s rastering (Mody, “Intervening”). For a time, Binnig and Rohrer resisted the computer when they first began presenting their work. The first public STM image, outside of their own personal visions, was created from oscilloscope lines that Binnig and Rohrer traced onto cardboard, cut out, and glued together to form a three-dimensional model of the sampled surface (Binnig and Rohrer, “From Birth” 401).32 The history of STM image development suggests that Binnig and Rohrer participated in imaging processes that encompassed or paralleled computer imaging capabilities, but did not entirely stem from use of the computer. (Chapter 3 further discusses imaging practices beyond computer-aided visualization, in relation to pictorial conventions.) However, Binnig and Rohrer switched over to the computer to generate images for publication. Other STM users followed suit when arranging their data, as the GUI (also developed in the 1970s, when the wave of non-lens-based scientific visualization technologies mentioned above occurred) afforded extensions of the interactive dynamics initiated by the data-gathering operations of the STM.
Characteristics of GUI also structure interaction, affecting what is imaged and how the resulting image is communicated. The fact that GUI use is now ubiquitous in scientific and medical visualization technologies (as well as in other technologies) makes the interaction dynamics of the GUI seem almost invisible; however, the interaction dynamics the GUI encourages help trace the influence of the GUI in STM use and in the production of STM images. The GUI affords STM users interaction with on-screen visual objects to manipulate in order to explore, change, or image the data. Interaction can affect the visual objects, as well as the data, with which the user engages. As information visualization researchers Dominque Brodbeck, Riccarde Mazza, and Denis Lalanne explain, with the use of computers (and the GUI), “graphical objects are not static anymore but can be interactively manipulated and can change dynamically” (29). In GUI interactions, the user expects to respond to visual objects (such as elements of images, or icons) as behavioral cues for manipulation, not solely in order to understand their meaning, or signification (Drucker, “Reading Interface” 215).
GUI characteristics affect STM use as well as image processing, as the STM user interacts with the GUI screen image in multiple ways, including while conducting the experiment, interpreting data from the experiment, processing the image for publication, and processing the image further if the image is intended to function outside of scientific journal articles (such as in press releases or on research group web sites). The user’s interactions with other dynamics, such as x, y, or z direction, allow the on-screen image to operate as an interface, thus allowing the image to function as an experiment and to help marshal evidence. GUI interactions structure the space in which the user interacts with the image, but also create a space in which the user interacts with the data and through the image with the nanoscale. The range of possible interactions that GUI enables reinforces the multi-directional and manipulable affordances created by electron tunneling, raster scanning, and z-direction moves.
Images and Experiments
GUI interactions also extend the time the researcher spends with the image and the data, further intensifying the imaging process. The arrangement of data in an image on a computer screen allows the user to turn the image into an experimental interface, coordinating with and amplifying the multi-directional affordance of the tip-surface interaction, or into what Daston and Galison call the “image-as-tool” (414). For example, in one of the experiments mentioned above, Jaklevic used images created by the STM to monitor an experiment. As interfaces, the STM images Jaklevic produced to observe the behavior of gold became events through which the researchers conducted the experiment. The involvement of Jaklevic and other STM users with the image (and the data) was intensified by incorporating the physical actions of the experimenters into repeated scanning and image constructions in order to conduct the experiment. The “Quantum Corral” image (Figure 4) is also a good example of how STM use becomes an event, as Eigler and other researchers created the nano-corral structure in order to conduct experiments on the electron standing waves they “caught” inside (Crommie, Lutz, and Eigler 218–220). The ability to use the STM image as an experimental space—to build structures (as in the case of the corral) or to observe events (as in Jaklevic’s experiment)—is part of what makes the STM a significant visualization technology. As Gimzewski et al. comment in the journal Surface Science: “Scanning probe microscopies (SPMs) . . . , and in particular scanning tunneling microscopy (STM) . . . , have revolutionized the real-space imaging of molecules, providing a detailed understanding of the ways in which they interact with each other and with adsorbents” (101). Gimzewski et al.’s observation highlights the focus on using the STM as a scientific tool for understanding interactions.
The STM encourages further interaction with the data through the image, as researchers engage in understanding the significance of the data. Amann and Knorr Cetina explain the mode of practice that involves assessing significance as one in which scientific visuals “act as a basis for sequences of practice rather than observation at a glance. They [visuals] are subjected to extensive visual exegeses, rendering practices which attempt to achieve the work of seeing what the data consist of” (90). GUI characteristics suit STM images well to this interpretive task, thus extending users’ interaction with the images. As one scientist I interviewed explained,
It’s [the experiment is] very much like putting something on a surface, seeing what it does, and trying to figure out exactly how it’s behaving, and there’s a lot of control experiments that you do between changing biases, changing tunneling currents, changing processing of the sample, to confirm like exactly what’s happening, how you’re looking at it.33
The ubiquity of the GUI, and the ability of researchers to use the same GUI to continue to interact with the image and explore and arrange data, while also making sense of the data and then producing images as evidence, all allow the user to go back and forth between Amann and Knorr Cetina’s observational, interpretive, and evidence-producing modes of practice. While microscope users have almost always manipulated samples being viewed to produce images, the GUI intensifies and structures the involvement of the STM user in all stages of image production (Keller, “Biological” 110). The STM user’s involvement creates a different relation to the image than if, for example, the user positioned the sample in an electron microscope and created an image, because the sample is destroyed in the process of viewing through an electron microscope, making only a limited amount of interaction is possible.
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