December 04, 2020 by Luke James
Spider webs have inspired a recent innovation from Purdue University, particularly in the field of photodetectors. This is as the formations that are weaved by spiders are not just complex and fascinating—they’re capable of forming very strong nets with high mechanical resistance.
According to the Purdue University researchers, the designs of spider webs have been used to perfect the technology behind 3D graphene photodetectors. The team’s research was published in Advanced Materials on the 12th of October and describes a fractal web design of a hemispherical (i.e. semi-spherical) photodetector array, which includes an effective photoactive component with enhanced light-absorbing capabilities.
The shape of the photodetector is combined with the mechanical properties of graphene in order to achieve a greater level of mechanical adaptability and damage tolerance. It also uses the structural architecture of a spider’s web, given that it exhibits a repeating pattern.
A photograph of the spider web-inspired fractal design used for hemispherical 3D photodetection. Image Credit: Purdue University.
“We employed the unique fractal design of a spider web for the development of deformable and reliable electronics that can seamlessly interface with any 3D curvilinear surface,” said Chi Hwan Lee, a Purdue assistant professor of biomedical engineering and mechanical engineering. He went on to provide the example of a dome-shaped photodetector—which was demonstrated in the research—that can detect both the direction and intensity of incident light at the same time. (This is very much reflective of how arthropods, such as insects and crustaceans, are able to see.)
According to the Purdue team, the photodetector’s spider web-inspired structure provides unique capabilities to distribute externally-induced stress through the threads according to the ratio of spiral and racial dimensions. This enables the structure to better dissipate force under mechanical stresses and other forces, such as stretching. The web architecture also resists minor cuts of the threads while maintaining its overall strength and fundamental function.
According to Muhammad Ashraful Alam, a professor of electrical and computer engineering who participated in the research, the 3D optoelectronic architectures are ideal for use in photodetection systems that require a large field of view and wide-angle antireflection.
Examples of such systems include imaging systems in biomedical and military applications. Alam adds that the Purdue team’s work establishes a platform technology whose applications are capable of integrating fractal web design with system-level hemispherical electronics and sensors—thus offering both high mechanical adaptability and resistance to mechanical loads.
“The assembly technique presented in this work enables deploying 2D deformable electronics in 3D architectures, which may foreshadow new opportunities to better advance the field of 3D electronic and optoelectronic devices,” said Lee.
