Consider the power of the prickly
porcupine. While underrated in the animal kingdom, these creatures'
barbs could hold the key to a host of new medical technologies. The
study "Microstructured barbs on the North American porcupine quill
enable easy tissue penetration and difficult removal," published today
in Proceedings of the National Academy of Sciences, sheds light on the efficiency of barbed porcupine quills in puncturing tissue and their resilience in, well, staying stuck.
predator's misfortune is a major step forward for the medical community
in terms of inspiring new devices modeled after the porcupine's
The Expert Take
The secret to
tissue penetration and retraction lies in the North American porcupine's
barbed quills. Its 30,000 quills each consist of a black tip with
backwards-facing barbs and a smooth white base with scale-like
structures. When confronted by predators, the porcupine releases its
quills, which easily penetrate the predator's flesh and are difficult to
The penetration process initiates a crack in the
tissue at the critical load, at which point the deployed quill punctures
the skin. The North American porcupine can not only exert less force
than its African counterpart without barbed quills, but it also damages
less surrounding tissue, as the stress concentration stretches or tears
tissue fiber in a cleaner fashion near the barbs.
showed that barbed quills also advanced deeper into muscle than do
quills without barbs. Quills with barbs require 54 percent less
penetration work and are more difficult to remove. Even an 18 gauge
hypodermic needle is no match for the barbed quill in terms of
smoothness of insertion and difficulty of removal.
Source and Method
from Brigham and Women's Hospital in Boston conducted a series of
penetration-retraction tests comparing polyurethane replicas of a
barbless control quill, a barbed quill, and a hypodermic needle to find
the relative penetration force (the force required for penetration into
tissue) and pull out force (the maximum force needed to remove a quill)
of the objects.
The research team's findings could lead to new mechanical
developments in medical technology, especially in the arena of needles.
The special barbed structure could become a model for cleaner, more
effective injection devices in hospitals.
to how biomimicry of cockleburs inspired the development of Velcro
hook-and-loop fasteners and the gecko is inspiring the development of
tape-based tissue adhesives, these findings should serve as the basis
for the bio-inspired development of new devices, including needles, for
easy penetration with compliant substrates, such as tissue, or
microneedles, where effective insertion without de-formation (buckling)
is required," the researchers wrote.
They added, "Mimicking the
porcupine quill should be useful for biomedical applications, including
local anesthesia, abscess drainage, vascular tunneling, and trocar
placement, in addition to the development of mechanically interlocking
of porcupines, published this year in Materials Science & Engineering
examined the composition of the North American porcupine's quills, with a focus on their keratin tissue structure.
Modeling devices after porcupine quills could be the future of medical technology, but their structure isn't perfect. This study,
published last year in the same journal, examined the physical structure and strains on North American porcupine quills.