Creepy crawling cadavers – can ‘necrospiders’ help microelectronic production?
Whether you love them or hate them, spiders play an important role in our ecosystem by keeping the insect population down. Without spiders, it is believed that our crops, and therefore our food supply, could be put at risk from insects eating through them.
But what useful purpose could a dead spider serve?
Well, plenty, according to engineers Daniel Preston and Faye Yap of the George R Browning School of Engineering, at Rice University – a global research and teaching school.
In 2019, the engineers discovered that spiders do not have antagonistic muscles like humans do. Antagonistic muscles work in pairs, so where one muscle contracts, the agonist, the other muscle lengthens or relaxes, the antagonist.
Instead, a spider’s legs only have flexor muscles, which means that the muscles decrease the angle on two sides of a joint, like the joint of a knee or elbow in a human – and in the case of a spider, their leg joints. These muscles allow the spiders legs to curl in, however, where a human would use their antagonistic muscles to extend their limbs, spiders use hydraulic pressure.
Yap claims that the research was prompted by an accidental discovery when she found a dead spider in the lab and wondered why their legs curled-in when they died.
After further investigation, they found that by inserting a needle into the spider’s hydraulic chamber, which is situated near their head, securing it with superglue, and inserting a syringe over the end of the needle, they were able to manipulate the spider’s legs to open and close by blowing a small amount of air into its hydraulic chamber.
The effect is a controlled creepy crawly that, when manipulated, looks entirely alive. They have been dubbed ‘necrobotic’ spiders for entirely understandable reasons. However, the team give assurance that the spiders are not reanimated, and that they remain completely inanimate throughout the process – despite appearances.
Experimenting with the use of the spider’s legs, or ‘grippers’, on several different materials, they found that a (wolf) spider could grab and carry over 130% of its own body weight. However, the bigger the spider, the lower the weight to body mass ratio it could carry.
What could they be used for?
Preston said: “There are a lot of pick-and-place tasks we could look into, repetitive tasks like sorting or moving objects around at these small scales, and maybe even things like assembly of microelectronics.”
Research found that the spiders’ joints began to wear down after approximately 1,000 cycles, however, they believe that with the use of polymeric coatings they can combat the joint dehydration, cited as the reason for the wear-and-tear.
So, who knows, maybe in the future an army of arachnids will be assembling microelectronic components. It certainly makes them an intriguing, and sustainable discovery.
The team further speaks about the sustainability of the ‘material’ itself. Spiders being of a natural ‘material’ are biodegradable, negating the use of hard plastics and metals. Preston added: “Also, the spiders themselves are biodegradable, so we’re not introducing big waste stream, which can be a problem with more traditional components.”
So, as creepy as these crawlies may be, they play an important part, not only in our ecosystem, but possibly in our electronics industry too.