MRS Meeting in San Francisco, California

Sean Ahlquist presents his research "Differentiating Fiber Structures in Knitted Textiles for the Generation of Deformable Material Systems and Architectural Skins" at the Spring Meeting for the Materials Research Society in the session titled "Adaptive Architecture & Programmable Matter: Next Generation Building Skins and Systems from nano to macro" on 8 April 2015.


Among a range of chemical processes, biological structures born of natural evolution define and tune ranges of material properties through the orientation and varied densification of fibers within a protein matrix generating differentiation, materially and geometrically, as a continuous medium. Viewed as pliable structures, the fiber orientation in natural systems serves as the critical parameter for tuning ranges of elastic deformation. This factor offers a critical comparison to architectural systems which conventionally rely upon rigid elements interconnected with hinges to provide means of geometric transformation. Fiber-reinforced composites, on the other hand, offer means for implementing concepts of elastically deformable natural systems as manufactured morphable material systems. While the primary concern for composites in architecture is its plastic nature designable for complex geometries, the ability to prescribe the fiber structure of the composite preform presents means for manufacturing materials of both a seamless and differentially deformable nature. This research explores the formation of textiles and reinforced composites through the use of advanced CNC machine knitting technology in generating a range of pre-stressed structural systems, oriented towards defining spatial, tactile and elastic material qualities. The material systems developed in this research vary greatly in scale, but explore conditions of patterning, surface texture and bi-stability, through a structural logic termed textile hybrid. Such a logic integrates pre-stressed (form-active) textiles with elastically bent (bending-active) fiber-reinforced composites, realizing form at the equilibrium of these structural actions.

This research explores, in depth, the fibrous nature of both system components through textile structures manufactured with CNC machine knitting technology, developed along a trajectory of (i) discretized systems, (ii) seamlessly integrated fiber-reinforced composite systems, and (iii) yarn-stiffened semi-rigid systems. Initial research explores the capacity of a knitted textile to tailor and direct forces when implemented as a tensile surface, within a boundary defined by bending-active glass-fiber reinforced polymer (GFRP) rods. Integrating diverse yarn qualities from elastic to structural, seamless materials are formed which internally house the textile hybrid behavior through the intermixing of pre-stressed regions and locally resin-impregnated areas within the continuous textile. Expanding the fiber diversity within a seamless textile, nylon monofilaments are integrated to define semi-rigid qualities without the need for resin-impregnation. This research involves collaboration with diverse knowledge sets from machine knitting defined primary by textile production for fashion, material science and aerospace engineering in defining the (diverse) performative nature of fiber-reinforced composites, and also interaction design in morphability as both a mechanism for passive adaptation as well as an actively manipulable and tactile interface.