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While discussing an article this morning here at Chez Chemistry World, Patrick spies the images inside and says: ‘Look, it’s the world’s smallest swingball!’ And here it is, the world’s smallest swingball.
What you’re looking at here is a microbead attached to a microthread tethered to a tiny pole. The team responsible achieved this by making the post structure, then adding a water-based photoresist to the sample. They trapped a silica microbead with optical tweezers in the liquid photoresist and used a pulsed laser to create the microthread, with the initial fabrication point on the bead. The free end of the thread was optically trapped and secured to the top of the post using multiphoton absorption polymerisation. They then optically trapped and manoeuvred the thread, wrapping it around the post. The bead was fastened to the side of the post using a polymer.
Next up is the one we initially thought was kind of like a desk toy for bored execs, but it’s actually more like a thread going through the eye of a needle. This is the microthread being manipulated to go through the eye using optical tweezers.
The team plaited one of the microthreads using optical tweezers as well, and created a maze and a pyramid. Looks as though John Fourkas and his busy team at the University of Maryland in the US have had a little fun with this! But, as well as demonstrating a concept, the structures do have a purpose: they could be used in biological applications such as mimicking structures in the extracellular matrix and to study individual cells.