drawtubes

Drawtubes are a class of drawing devices that employ hollow, flexible tubes to transport and deposit drawing material onto a surface, forming lines and patterns. They combine fluid dispensing with the mobility of a robotic or manual system, enabling direct patterning on irregular substrates.

They are typically made from silicone or other compliant polymers, with inner channels that range from tens of micrometers to millimeters in diameter. Materials are driven by small pumps, peristaltic rollers, or pneumatic actuation, and they use valves to regulate flow. The tip can be rigid, flexible, or heated, and some designs employ coaxial channels for multiple materials or colors. Positioning systems guide the tube or the drawing apparatus along the intended path, while sensors monitor flow, pressure, and occasionally the tube’s position.

Applications and contexts: They are explored in digital fabrication, flexible electronics, artistic installations, and soft robotics. In art, drawtubes enable continuous lines on curved surfaces; in manufacturing, they support rapid prototyping of circuits or patterns on nonflat substrates. They can provide high-resolution line deposition but face challenges such as clogging, material drying, and maintaining consistent line width.

Relation to other concepts: Drawtubes relate to pen plotters and drawbots but differ in the use of fluid transport within flexible conduits, which can enable drawing around obstacles and on complex geometries. Research focuses on improving material compatibility, flow control, and tubing durability.