Engineers Have Created a Clear Tape That Is 60 Times Stronger

Researchers at Virginia Tech have utilized the ancient Japanese art of kirigami to enhance the strength of sticky tape while also making it easier to remove. Led by Professor Michael Bartlett, the team has achieved a seemingly paradoxical combination of properties that could revolutionize various applications, including robotic grasping, wearables for health monitoring, and manufacturing.

Tape Based On Kirigami

The concept of easily removable tape originated in the 1920s when car painters required improved options for painting two colors on vehicles. Since then, tape manufacturers have introduced a wide range of products, such as invisible tape for gift wrapping, electrical tape for wire covering, and duct tape for numerous unconventional uses.

Traditionally, when tapes are peeled off, they separate in a straight line along the length of the strip until the tape is completely removed. Strong adhesives are challenging to peel off, while reusable adhesives tend to facilitate separation, limiting their strength. Professor Bartlett and his team sought to address this issue by manipulating the separation path inspired by the art of kirigami, which involves folding and cutting paper to create intricate designs.

Stronger Sticky Tape

The researchers introduced a series of U-shaped cuts across the adhesive, leading to a remarkable 60-fold increase in the bond strength of the tape. This engineered cutting technique forces the adhesive separation path to reverse, termed reverse crack propagation, resulting in a stronger bond. However, when peeled in the opposite direction, the tape easily comes off, exhibiting forward crack propagation.

Furthermore, the team discovered that the type of tape used was inconsequential. Kirigami cuts enhanced the bond strength of all tested tapes, including packaging and medical tapes. Strong adhesives became even stronger, and weaker adhesives experienced a notable increase in strength. The crucial factor was the shape and size of the cut, which determined the physics of the adhesive’s behavior.

Another advantage of this innovative approach is the rapid digital fabrication method employed by the researchers. This allows for the quick creation of highly customizable adhesives with adjustable strength, presenting exciting prospects for future adhesive development.