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

Dry water and Burning ice: all about gas hydrates

Two unusual materials with unusual names.  I show how to make "dry" water and propane gas hydrate, which looks like ice and is flammable.




Dry water
http://www.diva-portal.org/smash/get/diva2:1024928/FULLTEXT02.pdf

Propane clathrate
https://sci-hub.tw/10.1021/jp3035049

Propane hydrate formation
https://sci-hub.tw/10.1021/ie0207764

Methane storage in hydrates
https://sci-hub.tw/10.1021/ja8048173

Propane hydrate:
https://ps.uci.edu/scholar/sites/default/files/making_a_propane_clathrate_hydrate_1.pdf

https://www.netl.doe.gov/research/oil-and-gas/project-summaries/completed-env/fwp-feab112

Propane vapor pressure:
https://www.engineeringtoolbox.com/docs/documents/1020/propane_C3H8_vapour_pressure.pdf

Fumed hydrophobic silica on eBay:
https://www.ebay.com/itm/Hydrophobic-Fumed-Silica-Powder-2-Qt-64-oz-volume/123100048097


https://www.patreon.com/AppliedScience

Make plastic printed circuits with a standard laser cutter

I developed a new chemical process to make double-sided PCBs with a laser cutter, and some common chemicals.  This is intended to be used on SLA 3D-printed parts, but may work on many materials.




Refs:
http://infohouse.p2ric.org/ref/29/28004.pdf

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.527.5817&rep=rep1&type=pdf

http://shodhganga.inflibnet.ac.in/bitstream/10603/195088/3/chapter%202.pdf

https://sci-hub.tw/https://doi.org/10.1016/S0167-577X(03)00424-5

https://library.nrao.edu/public/memos/chem/CHEM_5.pdf

https://core.ac.uk/download/pdf/48645791.pdf


Support Applied Science:  https://www.patreon.com/AppliedScience

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

Engineering magnetics -- practical introduction to BH curve

A practical introduction to understanding magnetic devices such as transformers and motors. This video covers BH curves, reluctance, permeability, DC and AC magnetic circuits, and some applications. 

Please put questions in the comments, and I'll do my best to answer them! I apologize that I didn't mention inductance. 

This video focuses only on the magnetic side of things. Inductance is how the electrical circuit interacts with the magnetics.

https://www.patreon.com/AppliedScience