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Spiders understand “music” of their own web

June 5, 2014
Courtesy of Oxford University
and World Science staff

The sound of a spi­der web, plucked like a gui­tar string, pro­vides its in­hab­i­tants with in­forma­t­ion about prey, mates, and even we­b’s struc­tur­al con­di­tion, sci­en­tists have found.

The spi­ders use that qual­ity by “tun­ing” the silk, they say: con­trol­ling and ad­just­ing its prop­er­ties, and threads’ ten­sions and in­ter­con­nec­tiv­i­ties.

The find­ing comes from re­search­ers from the Uni­vers­i­ties of Ox­ford, Strath­clyde, and Shef­field in the U.K., who fired bul­lets and lasers at spi­der silk to study how it vi­brates. They found that un­like many oth­er ma­te­ri­als, spi­der silk is tun­a­ble to a wide range of har­mon­ics, or sim­ple pitch rela­t­ion­ships. 

The find­ings, to be re­ported in the jour­nal Ad­vanced Ma­te­ri­als, not only re­veal more about spi­ders but could al­so in­spire a wide range of new tech­nolo­gies, such as ti­ny light-weight sen­sors, the re­search­ers said.

“Most spi­ders have poor eye­sight and rely al­most ex­clu­sively on the vibra­t­ion of the silk in their web for sen­so­ry in­forma­t­ion,” said Beth Mor­ti­mer of the Ox­ford Silk Group at Ox­ford Uni­vers­ity, who led the re­search. “The sound of silk can tell them what type of meal is en­tan­gled in their net and about the in­ten­tions and qual­ity of a pro­spec­tive mate. By pluck­ing the silk like a gui­tar string and lis­ten­ing to the ‘e­choes’ the spi­der can al­so as­sess the con­di­tion of its we­b.” 

To study the son­ic prop­er­ties of the spi­der’s gos­sa­mer threads the re­search­ers used ultra-high-speed cam­er­as to film the threads as they re­sponded to the im­pact of bul­lets. In ad­di­tion, lasers were used to make de­tailed mea­sure­ments of even the small­est vibra­t­ion.

“The fact that spi­ders can re­ceive these na­no­me­ter [millionth-of-a-millimeter] vibra­t­ions with or­gans on each of their legs, called slit sen­sil­lae, really ex­em­pli­fies the im­pact of our re­search about silk prop­er­ties found in our stu­dy,” said Shira Gor­don of the Uni­vers­ity of Strath­clyde, a co-au­thor of the re­port.

“These find­ings fur­ther dem­on­strate the out­stand­ing prop­er­ties of many spi­der silks that are able to com­bine ex­cep­tion­al tough­ness with the abil­ity to trans­fer del­i­cate in­forma­t­ion,” said Pro­fes­sor Fritz Voll­rath of the Ox­ford Silk Group at Ox­ford Uni­vers­ity, an au­thor of the pa­per. ‘These are traits that would be very use­ful in light-weight en­gi­neer­ing and might lead to nov­el, built-in ‘in­tel­li­gent’ sen­sors and ac­tu­a­tors.”

“Spi­der silks are well known for their im­pres­sive me­chan­i­cal prop­er­ties, but the vibra­t­ional prop­er­ties have been rel­a­tively over­looked and now we find that they are al­so an awe­some com­mu­nica­t­ion tool,” said Chris Hol­land of the Uni­vers­ity of Shef­field, anoth­er co-au­thor. 

Added Mor­ti­mer: “It may even be that spi­ders set out to make a web that ‘sounds right’ as its son­ic prop­er­ties are in­ti­mately re­lat­ed to fac­tors such as strength and flex­i­bil­ity.”


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The sound of a spider web, plucked like a guitar string, provides its inhabitants with information about prey, mates, and even web’s structural condition, scientists have found. The spiders use that quality by “tuning” the silk, they say: controlling and adjusting its properties, and threads’ tensions and interconnectivities. The finding comes from researchers from the Universities of Oxford, Strathclyde, and Sheffield in the U.K., who fired bullets and lasers at spider silk to study how it vibrates. They found that unlike many other materials, spider silk is tunable to a wide range of harmonics, or simple pitch relationships. The findings, to be reported in the journal Advanced Materials, not only reveal more about spiders but could also inspire a wide range of new technologies, such as tiny light-weight sensors, the researchers said. “Most spiders have poor eyesight and rely almost exclusively on the vibration of the silk in their web for sensory information,” said Beth Mortimer of the Oxford Silk Group at Oxford University, who led the research. “The sound of silk can tell them what type of meal is entangled in their net and about the intentions and quality of a prospective mate. By plucking the silk like a guitar string and listening to the ‘echoes’ the spider can also assess the condition of its web.” To study the sonic properties of the spider’s gossamer threads the researchers used ultra-high-speed cameras to film the threads as they responded to the impact of bullets. In addition, lasers were used to make detailed measurements of even the smallest vibration. “The fact that spiders can receive these nanometer [millionth-of-a-millimeter] vibrations with organs on each of their legs, called slit sensillae, really exemplifies the impact of our research about silk properties found in our study,” said Shira Gordon of the University of Strathclyde, a co-author of the report. “These findings further demonstrate the outstanding properties of many spider silks that are able to combine exceptional toughness with the ability to transfer delicate information,” said Professor Fritz Vollrath of the Oxford Silk Group at Oxford University, an author of the paper. ‘These are traits that would be very useful in light-weight engineering and might lead to novel, built-in ‘intelligent’ sensors and actuators.” “Spider silks are well known for their impressive mechanical properties, but the vibrational properties have been relatively overlooked and now we find that they are also an awesome communication tool,” said Chris Holland of the University of Sheffield, another co-author. Added Mortimer: “It may even be that spiders set out to make a web that ‘sounds right’ as its sonic properties are intimately related to factors such as strength and flexibility.”