The "nano" in Nanox isn't

So, Nanox has been boasting in the technology section on its website: 

Over nine years of development by a Japanese and Israeli engineering team, produced a ‎stable Cold-Cathode field emission MEMS silicon‎. Using proprietary Micro-Electrical-Mechanical-Systems (MEMS) techniques, ‎millions of nanoscale gates are fabricated on each silicon chip. ‎Nanox emitters are far more uniform than carbon nanotubes (CNT) and are orders of ‎magnitude smaller than conventional Spindt-type cathodes‎. ‍

But is any of it true?  For example, has Nanox been able to miniaturize a technology that was a complete failure and make it potentially successful?  The answer is:  No!

If Nanox' emitters are "orders of magnitude smaller" than conventional Spindt-type cathodes, this means they are smaller than 1/100 the size of the "conventional" emitters (that's two orders of magnitude).  Here is how Nanox emitters are supposed to look like under an electron microscope (Slide 13, January 2021 JP Morgan presentation).

They look tiny, but how tiny are they?  Nanox is withholding that information.  Luckily, Nanox predecessor company has already published the original image - in early 2016, in a one-page "Nanox Technology Brochure" - with an embedded scale in it, like any regular image, or micrograph, generated from a commercial electron microscope.  All we have to do is use that scale to measure the diameter of the gate holes and the distance between them, and compare to say state-of-the-art Spindt emitters twenty years ago.

Aha.  So the holes are about 300nm in diameter and the distance between them is about 500nm.

And, what was the state-of-the-art twenty years ago, in year 2001?  Here is a picture from the Motorola paper titled "Field Emission Displays: a critical review" 

Uh-oh.  Turns out the Spindt holes from Candescent Technologies were actually smaller - 100nm in diameter, and intentionally placed at random distances.

Is it possible that somehow Nanox' team did not know about those developments twenty years ago?  Nope.  Here is why.  According to the unofficial history of the Spindt scam,  three years prior, Sony, desperate to maintain its relevance in the TV market, but completely clueless, joined forces with Candescent.

In November 1998, CTC announced an agreement with Sony Corporation for joint development of a 14-inch diagonal FED by the year 2000. Both companies pledged to spend $50 million on this effort. Most of the work would be performed at CTC's plants. A team of six Sony engineers were sent to San Jose to begin the work, with some additional staff dedicated to the project in Japan

Motorola had already canceled its project in 1999, thus the paper in 2001, due to inability to "solve some basic technology problems."  Candescent went bankrupt in 2004.  It took Sony a few more years to realize its mistake, but the $1 billion R&D spending is a complete myth.

So, to reiterate, ‎Nanox emitters are not orders of ‎magnitude smaller than conventional Spindt-type cathodes‎ - they are, in fact, LARGER.  Not that it matters, because Nanox, contrary to the false claims in the Prospectus and elsewhere, has no access to facilities to fabricate them commercially.

And the "nano" should have been a red flag anyway - MEMS in the supposed Nanox "Cold-Cathode field emission MEMS silicon" stands for micro-electro-mechanical systems.  Electro, not electrical.  Micro, not nano.  And there is nothing mechanical (moving) - the "electro-ns" do not count.

Ok, but what about those 100 million emitters in Slide 13 above?  Well, that number is possible.  Assuming those are positioned in a 10,000 x 10,000 square, and assuming 800nm distance between the tips, that gets us to a 8mm x 8mm "chip," ballpark.  But such a chip, even if it were real, is not changing anything.

In case anyone was wondering how big the Spindt emitters were 50 years ago, here is a diagram and a micrograph from the 1976 Spindt paper.  The gate hole diameter is 1,500 nm.  So Nanox emitter is just 1/5 of it, not 1/100.

Update March 29, 2021:  reworded and added the original Spindt emitter size.

Update March 29, 2021:  Wikipedia's page on Field Emitter Arrays have an interesting entry about nano-Spindts.

Nano-Spindt arrays represent an evolution of the traditional Spindt-type emitter. Each individual tip is several orders of magnitude smaller; as a result, gate voltages can be lower, since the distance from tip to gate is reduced. In addition, the current extracted from each individual tip is lower, which should result in improved reliability.

How did this incorrect and misleading entry wind up on wiki?  After checking the edit history, it turns out Nanox added it on December 22, 2015, a few days after the failed attempt by Nanox predecessor to market its fake cathode at RSNA 2015 (Nanox current CEO was then the Chief Strategy Officer).  Here is who added it:

My name is Joshua Lilienstein. I am an American medical doctor, now specializing in medical device development. I currently serve as Chief Medical Officer for Nanox Imaging, Plc., a Japan-based startup. Nanox's core technology is the field effect cathode. I will be editing entries that pertain to this technology, and specifically, in its application to medical imaging. I am aware of Wikipedia's Conflict of Interest policies, and will endeavor to abide by them.

At least he was honest about something.

He referenced an interesting paper that does not support his wiki entry in any way, but describes the long-lost x-ray detector, SAPHIRE, that was supposed to use nano-Spindts.  This is a flashback to the times when Nanox team "believed" that the x-ray detector was more important than the x-ray source.