Automated knot tying is difficult due to the inherent flexibility of string and wire. Instead of automated systems, some manufacturers use manual knot tying methods, or avoid knots altogether and use a different fastening means. Existing automated systems are complex and require regrasping of the string or wire, which increases the chances of dropping it and failing to tie a knot.
Dartmouth engineers have developed a method for tying knots in stiff, wire-like materials (e.g., steel wire or fishing line), and have designed a mechanism for tying overhand knots in wire-like materials (either in single strands or in bundles of strands). The knot tying method exploits the different behaviors of wire when it is pushed and pulled, and uses a knot shaped tube to guide wire into a knot. When the wire is in the right shape, pulling on the ends is sufficient to tighten the knot and remove it from the device. The device design is highly scalable, and can be matched to the thickness and flexibility of different materials.
This method has applications in a number of industries. In the medical field, it can be used to provide a simple means for suturing, particularly in situations where manipulation is challenging, such as laparoscopic surgery. Manufacturing applications include any of a number of industries that deal with wire or wire-like materials. The device even has potential as a toy. In its simplest form, the device is a mostly exposed tube, but this tube can be embedded into an opaque box, producing a magic knot tying box.
This technology is claimed in a pending US patent application. We are seeking an industrial partner interested in its commercialization.
Last Updated: 7/24/12