Ruxin Xie

Ruxin (pronounced as Ru-shin) is a researcher, designer, and lifelong maker. Her work lies at the intersection of art, architecture, mechanics, and robotics.  
She lives with a tabby cat named TT — Tiny Tiger. ᓚᘏᗢ

Curriculum vitae
Publications
Contact

2025
XXXBuildfest 2024Bethel, NY, USAXXIXRobotic SetupsPrinceton, NJ, USA
2023
XXVIIIThe ObservatoryCupertino, CA, USA XXVIITree House[Concept]XXVIGoogle StoreSanta Monica, CA, USAXXVCat LampCupertino, CA, USA
2022
XXIVSystems EngagementAnn Arbor, MI, USA
2021
XXIIICocoonAnn Arbor, MI, USAXXIISocial EquilibriaVenice, ItalyXXITopology Optimized Building Envelope Ann Arbor, MI, USAXXPoly-Fractal PackingAnn Arbor, MI, USAXIXPneumatic Origami Self FoldingAnn Arbor, MI, USA
2020
XVIIIDesign Ecologies of Glass[Concept]XVIIArchitecture {AI}[Concept]XVIVolumetric KnittingAnn Arbor, MI, USAXVShelf - Generative DeisignAnn Arbor, MI, USAXIVLight LeakAnn Arbor, MI, USAXIIITriByteAnn Arbor, MI, USAXIIMantaAnn Arbor, MI, USAXIHoursteelAnn Arbor, MI, USA
2019
XContext. Community. Co-op. Core[Concept]IXPlayscapeAnn Arbor, MI, USAVIIIExquisite LampAnn Arbor, MI, USAVIIKnitted InflatablesAnn Arbor, MI, USA
2018
VIEngageAnn Arbor, MI, USAVFantastic Beasts And Here They Are[Concept]IVAnimation and Architecture[Concept]
2017 and Earlier
IIISponge at Crossroad[Concept]IIBridge Church[Concept]IBirdwatching Pavilion[Concept]
Life

Drawings
Photography
Cooking




© 2017–2025 Ruxin Xie
Knitted Inflatables
Year
2019
Location
Ann Arbor, MI, USA
Status
Built
Material
GFRP, Nylastic, Aluminum Frame
Course
Independent Study
Affiliation
Taubman College, University of Michigan
Role
Led the textile team in translating the design concept into physical textiles. Learned and simulated the in-house scripting tool springFORM to generate mesh relaxation programming for 3D CNC knitting.
Instructors
Prof. Sean Ahlquist,
Tracey Weisman
Students
Ruxin Xie   
Tool Box
Rhino, springFORM, Processing


Monofilament
Polyester
Hytrel
Nylastic

This study uses 4 types of yarn, combined to create knits with unique shapes and properties. Different yarns and stitch types provide flexibility in designing complex knit patterns. Polyester, which produces flatter knits, was chosen as the main yarn for both the spacer and panel-to-panel designs with voids.

Silicone sealing better preserves the knit’s texture and features compared to TPU sealing. However, TPU sealing was used in the final studies for its stronger material binding and reliable performance. Future work could focus on improving silicone sealing techniques and designing knits optimized for inflatable applications.

The sealing process requires the fabric to be as flat as possible to ensure full sealing, whether using silicone or TPU. Spacer designs with “ribs” and the curvature caused by different yarn material properties create challenges due to their 3D forms. These issues can be addressed by using the same material for both the front and back layers, applying tension, and maintaining an even pattern during the sealing process.


 Knits are typically soft and flexible, but when enclosed and inflated, they can transform into structurally rigid forms. This study explores creating stiffness through constrained knits, departing from traditional approaches focused on expansion. I developed two knitting topologies for these systems. The first method creates a spacer volume layer between two knit surfaces. The second, a panel-to-panel topology, uses openings in tubular structures to generate strength when inflated. The fabric is sealed using either silicone casting or two layers of TPU (Thermoplastic Polyurethane) sheets, forming the necessary enclosure for inflation.




Topology 1: Spacer - Program
Topology 2: Panel to Panel - Program
Spacer knitting method is by applying a “spacer” layer in between front and rear knit to form a constrained knitting system. It is a rigid system which also has the potentials to be changed on knitting parameters, such as spacer’s stitch patterns, stitch length, and materials. The inflated effect will be different based on different knitting density and materials. 

Panel to panel with voids is another interconnecting method which allows the void area to be the connection between the front and rear knit. By designing different void patterns and locations where interconnection happens, it is possible for the entire knit to create a variety of flexible structure features when it is sealed and inflated.
Polyester + Hytrel + Polyester
Nylastic + Hytrel + Polyester

Hytrel + Hytrel + Hytrel
Polyester + Polyester
Nylastic + Hytrel + Nylastic
Polyester + Hytrel
 Topology
_Spacer

Yarn Type
_Front Knit: Polyester 720;
_Rear Knit: Polyester 720;
_Bind off: Nylastic

Stitch Length:
_Front: 10.2
_Rear: 10.2

Seal:
_TPU SheetsTopology
_ Panel to Panel with Diagrid Aperture


Yarn Type
_Front Knit: Polyester 720;
_Rear Knit: Polyester 720;
_Bind off: Nylastic

Stitch Length:
_Front: 10.2
_Rear: 10.2

Seal:_TPU SheetsTopology
_ Panel to Panel with Array Offset Varies


Yarn Type
_Front Knit: Polyester 720;
_Rear Knit: Polyester 720;
_Bind off: Nylastic

Stitch Length:
_Front: 10.2
_Rear: 10.2

Seal:
_TPU SheetsTopology
_ Panel to Panel with Apertures Sizes Vary


Yarn Type
_Front Knit: Polyester 720;
_Rear Knit: Polyester 720;
_Bind off: Nylastic

Stitch Length:
_Front: 10.2
_Rear: 10.2

Seal:
_TPU Sheets
Bistable Inflated Structure (Side 1)
Bistable Inflated Structure (Side 2)

Findings

The panel-to-panel method with voids enables flexible knitting designs. The placement and size of apertures influence the patterns, which exhibit distinct features in both inflated and flat forms. Testing revealed that some edges near the apertures separated from the TPU during inflation due to uneven air pressure across varying aperture sizes (image below). When apertures are spaced too far apart, the inflated pattern becomes less noticeable.

The aperture pattern plays a critical role in shaping the geometry and structural behavior of the knit. Both the size and location of apertures significantly affect the inflated forms, determining the overall performance and stability of the structure. Polyester bind-off produce flatter seams at the edges compared to Nylastic, which impacts how the fabric seals and inflates.

Bistable inflated structures, which bend in both directions, occur when compression forces act in opposite directions. This behavior introduces unique possibilities for structural applications, as it allows the knit to adopt stable configurations under varying conditions.
Conclusions

This study explores constrained knits as a method for creating functional, inflatable structures. By integrating computational design, material testing, and fabrication techniques, including CNC knitting and post-processing, it demonstrates how constrained knitting can address structural challenges in pneumatic systems.

Key findings emphasize the impact of aperture patterns on the inflated shapes and structural behavior of the fabric. Polyester yarn was chosen for its ability to create flatter seams, ensuring better sealing and stability. TPU sealing proved more reliable for material binding, while silicone sealing preserved the knit’s texture, presenting opportunities for future refinement.

The study also identifies the potential of bistable inflated structures, which maintain two stable shapes under opposing forces. This behavior suggests promising applications in adaptive systems and lightweight designs.

This work highlights the value of combining traditional textile craft with engineering, offering a foundation for further research into constrained knits and their broader applications.