The Society of Rheology 87th Annual Meeting

October 11-15, 2015 - Baltimore, Maryland


Poster Session

Spiders tune glue viscosity to maximize adhesion

October 14, 2015 (Wednesday) 6:05

Poster Session / Atrium/Harborview

(Click on name to view author profile)

  1. Amarpuri, Gaurav (University of Akron, Polymer Science)
  2. Zhang, Ci (University of Akron, Polymer Science)
  3. Diaz, Candido (University of Akron, Integrated Bioscience)
  4. Blackledge, Todd (University of Akron, Integrated Bioscience)
  5. Opell, Brent (Virginia Tech, Department of Biological Science)
  6. Dhiojwala, Ali (University of Akron, Polymer Science)

(in printed abstract book)
Gaurav Amarpuri1, Ci Zhang1, Candido Diaz2, Todd Blackledge2, Brent Opell3, and Ali Dhiojwala1
1Polymer Science, University of Akron, Cuyahoga Falls, OH 44221; 2Integrated Bioscience, University of Akron, Akron, OH; 3Department of Biological Science, Virginia Tech, Blacksburg, VA

Amarpuri, Gaurav

Adhesion in humid conditions is a fundamental challenge to both natural and synthetic adhesives. Yet, glue from most spider species becomes stickier as humidity increases. We find the adhesion of spider glue, from five diverse spider species, maximizes at very different humidities, that matches their foraging habitats. By using high-speed imaging we find that the glue viscosity varies over five orders of magnitude with humidity for each species, yet the viscosity at maximal adhesion for each species is nearly identical, 105-106 cP. Many natural systems take advantage of viscosity to improve functional response, but spider glue's humidity responsiveness is a novel adaptation that makes the glue stickiest in each species' preferred habitat. This tuning is achieved by hygroscopic organic salts that determine water uptake in the glue. We therefore anticipate that manipulation of hygroscopic salts to control viscosity will provide a simple mechanism to design humidity responsive smart adhesives.