Sunday, December 9, 2018

Laser diode self-mixing: Range-finding and sub-micron vibration measurement


A plain laser diode can easily measure sub-micron vibrations from centimeters away by self-mixing interferometry!  I also show how this technique can be used for range-finding.

http://sci-hub.tw/http://iopscience.iop.org/article/10.1088/1464-4258/4/6/371/pdf

https://www.jameco.com/Jameco/Products/ProdDS/2120428.pdf

https://www.spiedigitallibrary.org/journals/optical-engineering/volume-57/issue-05/051506/Overview-of-self-mixing-interferometer-applications-to-mechanical-engineering/10.1117/1.OE.57.5.051506.full?SSO=1

Nerd Thunder!  Check them out!
Dean Segovis: https://www.youtube.com/user/HackaweekTV
Jeri Ellsworth: https://www.youtube.com/user/jeriellsworth
Becky Stern: https://www.youtube.com/user/bekathwia
Ben Krasnow: https://www.youtube.com/user/bkraz333
John Schuch: https://www.youtube.com/user/HackersBenchTV
Darren Landrum: https://www.youtube.com/user/dmlandrum
Joe Grand: https://www.youtube.com/user/kingpinempire
Mark VandeWettering: https://www.youtube.com/user/brainwagon


https://www.patreon.com/AppliedScience

Sunday, November 18, 2018

MEMs oscillator sensitivity to helium (helium kills iPhones)



I tested the 32KHz MEMs oscillator used in some phones, and discovered that just a 2% helium environment will cause the oscillator to fail.  I also do a teardown of the MEMs device, and inspect it under the electron microscope.

iFixit blog post: https://ifixit.org/blog/11986/iphones-are-allergic-to-helium/  and vid:  https://www.youtube.com/watch?v=D0YLW6v5hrA


Original thread about MRI facility and iPhone failure on Reddit: https://www.reddit.com/r/sysadmin/comments/9mk2o7/mri_disabled_every_ios_device_in_facility/



MEMs silicon encapsulation:  http://micromachine.stanford.edu/~bongsang/pdf/Candler_2005_Transducers05_Hydrogen_diffusion_encapsulated.pdf

Applied Science on Patreon: https://www.patreon.com/AppliedScience

Sunday, August 19, 2018

Vintage electrical tech - Weston Sensitrol Relay

This vintage electrical meter is incredibly sensitive, and latches relay contacts with just 18 nanowatts!

Link to old Weston advertisement from 1950's:  https://pdfs.semanticscholar.org/7efe/c1a814298b121ecf67947183d3630db7f3b0.pdf

https://www.patreon.com/AppliedScience