Searcher A Low-Cost 3D Printed Micromanipulator for Precision ...
Searcher A Low-Cost 3D Printed Micromanipulator for Precision Neural Recordings Category: DIY Alternative I am colow-cost neuroscience tools for high school and early college students to begin learning about neurophysiology. We have designed amplifiers (the SpikerBox) and stimulators (the RoboRoach) that are currently in high schools and colleges around the world. We are now using 3D printing to solve one of our long-standing problems. A typical neurophysiology experiment involves placing electrodes close to neurons and then using amplifiers to detect the small electrical impulses. Our current experiments, viewable at: wiki.backyardbrains.com s whereby electrode pins are inserted by hand into earthworms, crickets, or cockroaches. With this approach, we are limited to experiments in animals with large enough neurons that precision is not necessary. For more sophisticated experiments, such as recording from individual cell types in fruit fly neurons/muscle or even specific ganglia in insects, manipulators are needed to carefully position electrodes near neurons or muscle tissue. Commercially available manipulators typically cost $500-$1000 and are made of high quality steel. Using a MakerBot Thing-O-Matic and Fig. 1: Top: Materials used in Searcher. Replicator, I have designed a micromanipulator Bottom: Completed Assembly with Electrode (Fig. 1) that requires only eight 3D printed parts attached and the following trivial components from online hardware store Grainger.com (the screws are cut to length with a common dremel tool). 13 - 6-32 machine nuts (1.9 cents each) 1 - 2.5 inch screws (10.5 cents each) 1 - 3.25 inch screw (12.7 cents each) 1 - 2.25 inch screw (10.5 cents each) 4 - 5 mm neodymium magnets (40 cents) - Exception: bought on eBay Total non-3D printed parts = $2.18
This manipulator has 4 degrees of freedom (an x-axis, y-axis, z-axis, and angle of attack), is hand operated, and has been used to successfully record muscle and neural activity in crickets and earthworms. The whole design was printed on a MakerBot Replicator within 3.5 hours and assembled within 1.25 hours using superglue, epoxy, and light machine oil. The magnets in the Our previous prototypes, made of 21 wood pieces, took a week to build and broke easily. Notably, we have also used our Searcher (Fig. 2) to record electrical responses from muscle tissue in optogenetic fruit fly larva (larva with special ion channels in their neurons that are sensitive to blue light).
Fig. 1: Left. A larva maggot preparation with electrode placed on muscle using our Searcher prototype (electrode is coming in from left side of picture). Right: Recording of electrical activity of muscle in response to blue light presentation.
This manipulator has 4 degrees of freedom (an x-axis, y-axis, z-axis, and angle of attack), is hand operated, and has been used to successfully record muscle and neural activity in crickets and earthworms. The whole design was printed on a MakerBot Replicator within 3.5 hours and assembled within 1.25 hours using superglue, epoxy, and light machine oil. The magnets in the Our previous prototypes, made of 21 wood pieces, took a week to build and broke easily. Notably, we have also used our Searcher (Fig. 2) to record electrical responses from muscle tissue in optogenetic fruit fly larva (larva with special ion channels in their neurons that are sensitive to blue light).
Fig. 1: Left. A larva maggot preparation with electrode placed on muscle using our Searcher prototype (electrode is coming in from left side of picture). Right: Recording of electrical activity of muscle in response to blue light presentation.
