• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1427-1432
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• 2008

This paper describes the locomotion of a water jumping robot which attempts to emulate the fishing spider’s ability to jump on the water surface. While previous studies of the robots mimicking arthropods living on water were focused on recreating their horizontal skating motions, here we aim to achieve a vertical jumping motion. The robot jumps by pushing the water surface with rapidly released legs which were initially bent. The motion is triggered with a latch driven by the shape memory alloy actuator. The robot is capable of jumping to the maximum height of 26mm. Jumping efficiency, defined the maximum jumping height on water over the maximum jumping height on rigid ground, is 0.26 This work represents a first step toward robots that can locomote on water with superior versatility including skating and jumping.

• Applied Microscopy
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• v.38 no.2
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• pp.89-96
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• 2008

Dolomedes spiders of the family Pisauridae are one of free wandering spiders with semi-aquatic habitation. They do not build web for prey-hunting but build a nursery web for spiderlings. This paper describes the fine structure of the silkspinning spigots of the fishing spider Dolomedes sulfureus revealed by the field emission scanning electron microscope (FESEM). The fishing spider Dolomedes sulfureus possesses only three types of silk glands which connected through the typical spinning tubes on the spinnerets. The silk spigots of this spider were identified as three groups: ampullates, pyriforms and aciniforms. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another two pairs (or $1{\sim}2$ pairs in males) of minor ampullate glands supply the middle spinnerets. In addition, the pyriform glands feed silk into the anterior spinnerets ($62{\sim}68$ pairs in females and $45{\sim}50$ pairs in males), and the aciniforms send ductules to the middle ($33{\sim}40$ pairs in females and $18{\sim}25$ pairs in males) and the posterior spinnerets ($42{\sim}50$ pairs in females and $24{\sim}28$ pairs in males). Among these, the ampullate one is the most predominate gland in both sexes.