Transgranular Perspiration is Not Sandy Sweat: New Discoveries in Ceramic Tiles at smartgeometry 2012
Since the early 2000s, the smartgeometry conferences have been held in venues as august and varied as San Francisco, London, Barcelona, and Copenhagen. At first glance, Troy, New York—this year’s location—seems a little out of place in that lineup, but in fact smartgeometry 2012 was another spectacular event and Rensselaer Polytechnic Institute (RPI) proved to be the best possible host for this annual gathering of VSPs (Very Smart People) who are finding new ways to apply computational design to pressing real-world problems.
[pullquote_right]A few days of frenetic competitive effort in an atmosphere that resembles cram night at MIT crossed with a MythBusters episode.[/pullquote_right] But what’s smartgeometry? Aside from an organization that prefers lowercase nomenclature? Founded in 2001 by superstar architects Lars Hesselgren, Hugh Whitehead, and J Parrish, together with computer scientist Robert Aish, the smartgeometry organization and annual conferences are largely responsible for the increasing presence of computational design (also known as generative design) in architecture, where the iterative, model-based, algorithmic techniques are used to design buildings that could not exist otherwise. But smartgeometry no longer focuses exclusively on architecture; especially in the last few years it has become a community of super smart, super passionate people from business and academia (including students) who seek to apply computational design techniques in many arenas and at many scales.
And when this community gathers at conferences, they aren’t content to just sit around listening to talks. Instead, smartgeometry always features ‘workshops’ where ‘clusters’ of a dozen or so work with sophisticated tools like CNC machines, kilns, 3D printers, and dozens of workstations to pose and answer questions with physically embodied results. At the smartgeometry conferences I have attended I have seen motion-sensing tables enabled by Kinect hacks, buildings made of lath and compound curves, wearable sensor systems that briefly overwhelmed Google Maps in Copenhagen, programmable woven textiles that writhe when touched, acoustic systems that track and amplify individual performers, and sundry other wonders all brainstormed, created, invented, in a few days of frenetic competitive effort in an atmosphere that resembles cram night at MIT crossed with a MythBusters episode. And this is why Troy and RPI work just as well as London or Copenhagen; ultimately it doesn’t matter where smartgeometry takes place, so long as the brainiacs are given sufficient bandwidth and workshop space—the fact is, they aren’t here to sightsee, and they aren’t going outside anyway.
Clusters are groups of a dozen or so that focus on pre-determined topics of interest. At Troy, since the conference theme was, “material intensities,” clusters included themes like, ‘material conflicts,’ ‘ceramics 2.0,’ ‘bioresponsive building envelopes,’ and ‘gridshell digital techtonics.’ A cluster that caught my eye, and that I’d like to talk about in detail here, was ‘transgranular perspiration.’ To quote from its prospectus:
“The cluster investigates the relationship between geometry, ambient conditions, and ceramic composite material in the production of an adaptable, environmentally reactive chamber. The chamber is made from prefabricated ceramic parts made in a portable kiln, allowing grafts onto the existing framework.”
That’s a mouthful, but it comes down to this; clay is one of our oldest building materials, and there is still a lot to be learned about its capacities. “Clay is a cheap, abundant material,” says cluster co-leader Brian Lilley, “If we can learn to use it more effectively to create passive comfort—for example if we can direct and store thermal gain and moisture more efficiently—we’ll have made a significant contribution to sustainable building practices.”
Specifically, at smartgeometry 2012, this meant learning more about the thermal and absorptive properties of fired and green clay combined into single tiles (the ceramic “composite” referred to above) and used as exterior wall coverings. That sounds like relatively low-tech work, but as Lilley and his co-leader Roly Hudson (both of whom teach architecture at Halifax’s Dalhousie University) conceived it, the learning process ultimately involved real-time sensing of heat dissipation and moisture migration, sophisticated virtual modeling and optimization in Bentley System’s GenerativeComponents, rapid prototyping and firing of new tile designs, and even some electron scanning microscope work. The cluster was an excellent demonstration of one of smartgeometry’s most closely held convictions; if you give dedicated people access to the best digital and physical tools, and let them bounce ideas off each other, they are likely to design and build extraordinary things.
Here’s how the cluster looked to visitors: A large steel framework was fashioned so that large tiles, about 12″x12″, could be quickly mounted and arranged. Heat lamps, sprayers, and sensor were aimed at the composite tiles, and (literal) heat maps of sensor data, continuously updated, were projected onto the tiles as they were heated and cooled, wetted and dried.
“The real-time aspect was essential to gain more intuitive understanding of the system,” says Hudson, “In terms of the model we could confirm what logic and our knowledge of the physical principles of the ceramic indicated. A more long term goal is to use the real time information to determine changes to the wall configurations so we can implement moisture movement and heat transfer from specific known points of higher energy to target locations. With the embedded sensor network we could make changes to the wall and verify if our predications were correct. Again, this is about gaining a deeper understanding of the basic physics of the material.”
Essentially, the reinforcement of real-time feedback helped to confirm or correct intuitive knowledge of clay properties, and that knowledge led to more inspired tile design. “Even in a heavily conditioned environment, we learned that most of our assumptions about thermal gain were spot on,” says Lilley, “In fact, there was a substantial heat and humidity ‘flywheel’ affect, so that energy absorbed in the mornings, due to solar gain, was released in the evening. But we also learned a lot of new things about the way the green and fired clay worked together, and that informed our ongoing tile design.”
Fired clay is a familiar and relatively well-understood material; it’s hard, for example, brittle, not very porous, etc. Green clay, by contrast, is somewhat mysterious; though it’s been used for millennia in traditional building methods like cob and adobe, green clay—clay that is shaped, hardened, and used without kiln firing—is not really part of the modern builder’s toolkit. In this cluster, Lilley and Hudson, together with materials engineer Kevin Plucknett, also of Dalhousie University, and Rory Macdonald, a ceramics professor of NSCAD University, were layering green clay onto fired tile substrates, exploring ways to use the varying properties of each synergistically.
The 14-member team, mostly students, quickly learned that the porosity of the composite was interesting and hard to analyze. That’s where the GenerativeComponents model was useful. “If we could control porosity, we could control the way water was absorbed and released. So it was important to understand this,” Lilley explains, “There had been previous work addressing ceramic porosity in large clay bodies, which we borrowed from Soil Mechanics. In particular, Flownet modeling based on Darcy’s Law has been used as a starting point. Together with our own data, we have done modeling in GenerativeComponents that indicates, for example, how pore dimensions, viscosity, and the depth of the porous surface affect absorption and release. We were especially interested in how our assumptions applied at different scales.” This iterative process—predict, test, measure, refine model, predict—combined with rapid prototyping allowed the team to quickly evolve new tile configurations over just four days, and measurably improve the performance characteristics they sought to optimize.
“We were able to understand the physics of the micro-scale, and bring those lessons up to the macro-scale,” says Lilley. This understanding led to changes in surface patterns that, among other desirable factors, decreased cracking and improved substrate bonding.
The knowledge gained at smartgeometry was substantial, and provides a foundation for a significant next step; “We’re ready to apply this to a small project this summer,” says Lilley, “A kitchen oven in a community garden. It will be a clay structure with a number of embedded properties, including predictable storage and use of moisture and heat.”
Lilley got his start as an architect working on the GSW headquarters building, in Berlin. At the time, it was the world’s 2nd large building to use a double facade for passive temperature regulation, and it remains one of Europe’s most energy efficient high-rises. “It really made an impression on me,” he says, “Achieving comfort with passive devices is good knowledge capital, and I’ve continued to explore that.” The composite tile system is also an excellent example of knowledge capital; even though the design techniques are sophisticated, the fabrication techniques aren’t, and can easily be applied in impoverished regions. The expertise developed in Troy, NY, may one day make life more comfortable for millions.
Bentley Systems, GenerativeComponents, & RPI
There are other smartgeometry sponsors besides Bentley Systems, and a lot of software other than Bentley’s GenerativeComponents is used, but both continue to be incredibly important to the success of smartgeometry (which is completely run by volunteers) and, by extension, to the whole field of generative design. Bentley, for example, was the sole platinum sponsor of this year’s smartgeometry, and the importance of their support can hardly be overestimated. This is especially true in connection with GenerativeComponents; Bentley basically invented the concept, developed it into commercially viable software… and then decided to give it away for free—it can be downloaded at www.bentley.com/en-US/Promo/Generative+Components/Special+Offers.htm)
GenerativeComponents is a standalone parametric CAD tool that perfectly suits the algorithm-heavy, multiple-variable problems faced by cutting edge designers. It’s language-based and not exactly intuitive, but according to Robert Woodbury, author of Elements of Parametric Design, “GenerativeComponents has a steep learning curve and great power.” That power is evidently popular with the smartgeometry community; GenerativeComponents and related Bentley software like AECOsim Energy Simulator was used heavily in eight of the ten clusters at smartgeometry 2012.
The host of this year’s event was Rensselaer Polytechnic Institute which was founded in 1824 and is—who knew?—”the oldest technological university in the English-speaking world,” (and if more credibility is needed, RPI has also hosted an episode of MythBusters). Most of the smartgeometry participants spent most of their time at RPI’s multi-venue art center, the Curtis R. Priem Experimental Media and Performing Arts Center (EMPAC). It’s a stunning building, and one of the world’s most technically progressive performance spaces. It’s also an acoustics laboratory, among other things, and a perfect home for smartgeometry’s workshop component. It was also, of course, a perfect spot for the event’s symposium, where journalists like myself felt the need for a RAM upgrade as we listened to the presentations of findings. RPI also pitched in by providing full access to ceramics workshops, science labs, CNC machines, workshops, everyday tools, and basically anything else that was needed.
Ultimately, RPI’s location in a relatively obscure corner of New York State didn’t matter one whit; the tools, people, and organization were the important thing, and the concepts proved out at smartgeometry 2012 will resound for decades to come.