Synthetic Biology

Synthetic Biology

Lifeobject is an installation at the 15th Venice Bienniale (2016), that explores bio-mimetic architecture. It is a bird’s nest-like structure, based on scans of an actual bird’s nest, made of fiber-reinforced polymer (FRP) ‘twigs’, that is said to respond to human presence. It is a collaboration of architects and scientists, and forms the primary focus of the Israeli pavilion at the Bienniale.

(The exhibit’s website, www.lifeobject.net, is eloquent about the concepts but not too explicit about key details, so some of the following description must be considered assumptions rather than facts.)

The LifeObject website describes it thus:

“LifeObject presents a “living structure” that responds to its environment. 11 breathing cells, dispersed within the LifeObject which react to the visitor’s presence, revealing cabinet de curiosités inside each cell. The breathing cycle of the LifeObject system relies on the use of smart materials, which function as sensors and actuators, activated and triggered by visitor’s presence.”

(It also mentions that over 100 people took part in the creation of it, and it’s a little unclear on who actually designed and created the LifeObject.)

The nest of a Jordan Sparrow was scanned and analyzed to determine the relationships of its twig sizes and placement. From this data, an algorithm was created tow reproduce the twig relationships in a differently-shaped structure. The sparrow uses certain larger twigs to anchor the nest to a branch, so 25% of the FRP twigs were chosen and assigned fixed placements that define the overall structure. The remaining 75% were interwoven with the fixed ones in a much more loosely located plan, allowing the builder “planned degrees of freedom.”

The twigs that comprise the nest vary from 1cm to 5 cm I diameter, and are made of aramid fibers and glass fibers in an epoxy matrix. Its 1500 twigs describe a volume of 3 m3. Of the forming process, the creators comment: “In contrast to standard FRP fabrication processes, the fabrication and shaping of the elements relies on the fabric materiality of the composite rather than on moulds.”

Glassfiber and aramid are knit in long, thin, tubular shapes. The tubes are saturated with wet resin, and then hard rings (or an unspecified material) are inserted inside the tubes, at intervals. When the tubes are stretched, the rings open the tubes to their full diameter at certain points, rather like the nodes of a natural bamboo stalk. In between the nodes, the tension closes the diameter down partially, resulting in a very twig-like appearance. They are cured in this stretched condition, and take the twig shape permanently.

The open lattice that formed this way is rather unusual in the world of composites, and may be the most innovative thing about the LifeObject. It is strikingly similar to the woody lattice that is the structural skeleton of certain cacti such the cholla cactus.

cholla-img_0477-crop twig-cu

 

 

 

 

 

 

This method of forming is highly innovative. (Forming innovations seem to be one of the biggest growth areas in composites research lately.)

The responsive aspect of LifeObject relies not on FRP, but on metals, specifically memory alloys, which the Lifeobject folks describe as “smart materials.” The responsive elements have been dubbed “breathing cells” but they are really little theaters: a glass ball with a biological exhibit inside, and a curtain of metallic strips surrounding it, closing it off from view. When a human is nearby, the strips part, the curtains opens, to reveal its enclosed wonders.

Lately, when we speak of a machine or an electronic system “sensing” human presence, we think of light-, motion-, capacitance-, or heat-sensing devices that are networked to a central control that can activate a mechanical system such as (for instance) a curtain of metallic strips. But not in this case.

LifeObject’s breathing cells respond directly. The memory alloy strips have two different shapes that they can hold, depending on temperature. In their lower-temperature state, the form a closed curtain. The heat that human visitors generate causes them to change to their other, more rounded shape that creates of opening of the curtain.

Although this curtain effect may not be scalable into human-sized self-opening doors, it does get you thinking. Smart materials that can respond to changing environments and human interactions without a lot of secondary mechanics to operate them or electronics to control them could be more efficient than having to network everything to a central command.

You can read a lot more about it at www.lifeobject.net.

Images via lifeobject.net and designboom.com, as noted.