Talk:Microelectromechanical systems

Applications???

It seems to me that this article could be VASTLY improved by the addition of a section on APPLICATIONS, which gives a reasonably complete overview of what MEMS can be used for. I'm no expert, so don't feel qualified to write the section, but surely some applications experts are out there. Also, a brief description of how a MEMS device accomplishes the listed applications would be useful, or else a link to a real article that does that. For example, I'm aware of applications such as mechanical resonators and filters, capable of extremely high performance and miniaturization, and molecule-specific or pathogen-specific biosensors, and some pretty good approaches to the "artificial nose" based on the latter. Also is it not true that highly miniaturized gyroscopes and inertial sensors have been built using this technology? That's far from a complete list, but perhaps it will kick off an effort to improve the article's coverage of applications, so that readers will start to know why they even care about MEMS technology. — Preceding unsigned comment added by 64.134.243.9 (talk) 01:15, 17 March 2013 (UTC)

Question about size range in which its called micro-machining

I wonder what the largest structure size is that is still considered micromachining? What about pieces just below one mm? C9g 04:34, 30 August 2007 (UTC)

Plagiarism of "Etching Processes"

Most of the content under "Etching processes" is lifted directly from [[1]]. It appears the original source is copyrighted and not cited in the article. 138.67.5.173 21:49, 23 October 2006 (UTC)

• You are right. I re-wrote that paragraph. Glaurung 06:25, 25 October 2006 (UTC)

(old chat not related to improvement of the page)

i am depositing gold film of 0.5 micron thickness over a pattrened wafer which is thereafter going for bulk micromachining in KOH solution. i am obeserving that gold is pilling out form the surface where beneath layer is silicon. is it possible that Au adhesion is poor with Silicon, or the pin holes are main culprit in this. please suggest.

Au adhesion is known to be poor on Si. Try a thin Cr or Ti underlayer first as they will bond more strongly the with the native oxide on the Si. 5 nm should be enough. Alison Chaiken 14:59, 27 January 2006 (UTC)

Also Au is solubile in Si. Perhaps this removes the Au next to Si so the adhesion is lost by removing material at the interface.--Peterpall (talk) 06:03, 29 June 2016 (UTC)

hmm

MEMS is also the acronym for a middle school in New Jersey- Manalapan-Englishtown Middle School

Microsystem technology

I have doubt about the new sentence that was added : In Europe, MEMS are often referred to as Micro Systems Technology (MST). I have personally never heard these words when talking about MEMS, and I was told they were only used by German-speaking people as a direct translation of Mikrosystemtechnik. 07:07, 28 February 2006 (UTC)

That may be true. I was doing an edit of the MST accronym page and the first entry was Micro Systems Technology. I had a look at the Micro Systems Technology page -- here is what I saw orginally [2] -- it just said it was a European name for MEMS. I figured why have a separate article of two sentences, why not just a redirect and explain that MEMS has another name in Europe. If you feel it is wrong we can change it. --Ben Houston 15:47, 28 February 2006 (UTC)

Before writing on this talk page, I looked at the edits to see where the info was coming from and I saw what you did. I should have made it clearer that I was in no way pointing at you personally with my remark. The original edit was made by an anonymous user, so we don't know where he is coming from and what his sources are. It would be interesting to have information from Europeans wikipedians with knowledge about MEMS, to decide whether MST is widely used in Europe or only in German-speaking countries. All I can say is that in the French-speaking part of Switzerland, we do not use microsystem technology, but I would not take this as a reference. Glaurung 07:10, 2 March 2006 (UTC)

Ah, I understand. Well, I just did a search and there is a quite a few mentions of "Microsystem technology" on the web (16,100 if I exclude wikipedia related results)and there seems to be a few research groups that use that name [3], [4], [5] (the page title is MEMS, the title within the body is "Micro-Systems Technology".) The term's popularity via Google, even if it is semi-equivalent, is 1000x less than MEMS. Thus I think it warrents a redirect and a very brief mention. --Ben Houston 16:06, 2 March 2006 (UTC)

Accodrind to your links, it is also used in England, so European seems to be applicable. (On a side note, one of your link is in S. Korea, so MST may be even more widely distributed.) A redirect to MEMS, is naturalle very suitable in this case. Glaurung 06:55, 3 March 2006 (UTC)

I believe MEMS are known as microsystems in Europe. A new EU-backed activity called STIMESI (Stimulation Action for Microsystems and System and Package)has recently started up.

Introduction

Consider starting the intro with something a little more layman friendly. I'm an engineering student and I was getting lost by the second sentance. I imagine someone with a non-technical background will get even less out of it.

My suggestion would be start of with the applications and especially the motivation for using mems over older technologies that could perform the same tasks. it seems like this could be seperated from the manufacturing details that are currently in the introduction.

I agree in that the introduction is not very good. The second sentence sets MEMS in relation to Nanotechnology. What kind of definition is that? It just introduces another concept that is probably unfamiliar to the reader. It is ok to explain the relationship between the two, but this should not be done in the lead!

Jonas Henriksson (talk) 16:25, 29 March 2013 (UTC)

my aggravating brain keeps me mulling over the intro part generally stating 'microelectromechanical systems, also written as microelectromechanical systems.'

With it being, in part, parenthetical, I have no idea if it's just me or a decent way to deal the rest of the words in parentheses as well.

Steven Kirkland ^(talk) 12:59, 27 August 2021 (UTC)

External links

The external links are getting too numerous (if one follows WP:EL). However, due to the diversity of the field I think we can live with an above-average number of links, at least until the wiki content has expanded reasonably. In the meantime, I have started some cleaning by separating research institutions from foundries, and skipping vendors (actually one so far) of MEMS based systems. --DrTorstenHenning 11:30, 7 August 2006 (UTC)

• Someone keeps adding a particularly annoying link to memsinvestorjournal.com, misleadingly labelled as "Interviews with MEMS industry leaders", while this site is in fact just another newsletter on MEMS. It is my interpretation of WP:EL that, since we cannot have a list of all the newsletter sites in the world, we should have none such sites. Any opinion on this? --DrTorstenHenning 08:02, 17 August 2006 (UTC)
  • OK, seems I'm only talking to myself here, yet the link list keeps growing and growing. I've marked it for cleanup, and will give it some time before actually cleaning up this messy dump of links. --DrTorstenHenning 12:59, 26 August 2006 (UTC)

I concur too many external links... but the page is so poorly written that, well, as a temporary measure it is not too bad. Interestingly there are a few links that have been removed which could have been left (including one to a site I maintain A (not so) short introduction to MEMS, which, well, in all objectivity :-), was probably useful, but there was at least another one to a good online intro that has been removed too...). I let you judge what is worth including - but chop the list!

• I inserted that link you mentioned (less the typo:-) I agree that as long as nobody takes the time to thoroughly rewrite this article, the links are better than nothing. I just try to keep the links sorted, so that NPOV info sites do not get mixed up with commercial interest motivated web sites. Wish I had more time at hand ... --DrTorstenHenning 16:48, 20 September 2006 (UTC)
  • I'm removing some spam and unsuitable links per WP:EL. Canaima 23:11, 18 February 2007 (UTC)
• I continue to add an external link to the MEMS Net and MEMS Exchange since these are US Govt infrastructural efforts in the MEMS field, are not commercial organizations, and are not spam as the user Canaima seems to indicate. If Canaima wishes to contact me to allow me to explain what we do and our role in MEMS I will be glad to talk to them, otherwise I suspect that this person's efforts are a disservice to the community - Dr. Michael Huff, Director of the MEMS Clearinghouse and MEMS Exchange. —Preceding unsigned comment added by Michaelhuff (talk • contribs)

Michael, good that you got an account; you can sign talk comments using four tildes; do so and you can remove this comment and unsigned remark above. Dicklyon 22:37, 24 February 2007 (UTC)

• • Again, I have gone back in replace an external link for the MEMS Exchange. The person who keep removing this should contact me and discuss. My contact information is on the MEMS Exchange web site. Thanks.

You seem to misunderstand how Wikipedia works. A number of editors have reviewed your added link and deemed it inappropriate according to the external link guidelines. I actualy think the MEMS net link is worth keeping, the Exchange link really should go. It's just a consulting service. Wikipedia is not a directory of links - see guideline WP:NOT. There is no encyclopedic information about MEMS, except the promotion of a service (again something Wikipedia is not). The only thing worth link at the url is the FAQ, but it the same information is already available on the Net site. So, not only does the link not pass the external link guidelines WP:EL, it is also redundant. I am removing it again, and I encourage you to wait until other editors decide if the exchange link is a valid addition. You should not have added the link in the first place since it is a clear "conflict of interest" see WP:COI. Nposs 02:52, 18 March 2007 (UTC)

• Yes it would appear that I do not know how this works. I see MEMSX which is a commercial organization having an external link and the MEMS Exchange which is a non-profit organization (it is not a consulting service by the way) sponsored by the US Govt getting the boot. It seems a bit strange to me. Also I disagree that the only worth link at the URL is the FAQ, the process catalog on the MEMS Exchange site is widely used and referenced by people in the MEMS community and is not available on the MEMS Net site. [Michael Huff]

I think this is the link to the process catalog that you are talking about: http://www.mems-exchange.org/catalog/. This might actually be worth linking since it includes relevant information that could not be accomodated in an encyclopedia article. If you can explain more clearly what it is, I think it could be worth adding. Nposs 22:40, 18 March 2007 (UTC)

• The process catalog is a database of individual processing steps that are used to fabricate MEMS devices. Each process entry in this catalog includes a variety of very useful technical information that is important to MEMS designers such as deposition rates, thin film stresses, indexes of refraction, chemistry, etc.

Thanks for explaining. I'm concerned that many of the processes don't contain very detailed information, but others contain jpgs and other useful information. I've linked with a neutral, descriptive title. Others might find the link to be too promotional (since it is basically selling the services of a specific fabricator) and might remove it. Thanks for discussing it, though. Nposs 03:03, 20 March 2007 (UTC)

Someone's back at trying to add MEMS exchange links in again. Anyone care to chime in and defend this? I'm against having them, for arguments espoused by others a year ago, written above.--Cubic Hour (talk) 20:02, 7 November 2008 (UTC)

• All the external link re gone by now... it is maybe extreme - I add an open online book on the topics that is still maintained Aveclafaux (talk) 07:32, 10 August 2018 (UTC)

Electro-mechanical coupling

Many MEMS devices are based on electro-mechanical coupling but that is not mentioned on the page. Also one could add the fields of physics which MEMS devices combine: electromagnetics, solid mechanics, fluid dynamics, and heat transfer. There's quite a lot of text on the manufacturing side but not so much on the operating principles. Do you think it would be helpful to add something on these? -[Apursula, 28-Aug-2006]

Definitely yes, this article aought to be expanded considerably. So far, most of the edits have consisted of dumping ever more external links. I wish I had more time at hand right now, so please go ahead and add the things you mentioned. --DrTorstenHenning 12:13, 28 August 2006 (UTC)

Para 2 from a investment journal?

Para 2 seems to be ripped from a investment journal. In anycase there should not be a investment or corporate focus this early in the article. If it is not plagarised, somebody should summerise it and give it less emphasis. —The preceding unsigned comment was added by 202.161.23.124 (talk) 04:51, 9 December 2006 (UTC).

Clarity of article

At the point the article says "These devices" (3rd of the way down the first para), there is confusion about which devices are being referred at this point because the article title is about MEMS but the previous sentence had discussed Molecular technologies. It doesn't read well and makes the reader guess a little.

Xenon DiFluoride and References

I agree that a reference to an etching model is not consistent with the rest of the article. But I think the fix should go the other way - each etching method should point to a paper in the literature that describes the method in detail. A survey paper would be best if one exists.

Also, I know Berkeley did this XeF2 work very early. Surely there is a technical report, conference paper, or journal submission you can cite to show this.

Finally, in the phrase "Its etch selectivity to silicon is very high", you do not want "it's", which is an abbreviation for "it is". You want "its", which is a possessive adjective. See ITS. LouScheffer 22:59, 14 July 2007 (UTC)

Should microsystem be made a redirect?

They (-the two articles) seem to be the same thing, but I'm worried that microsystem might have information that isn't included here... So if someone is familiar with this article, can you check that quickly? Otherwise, I'll get to it myself eventually, but I don't have time to read the whole article right now. ^^ --Oracleoftruth (talk) 13:18, 19 March 2008 (UTC)

The term Microsystem and MicroSystem Technology MST are used as synonyms with MEMS in Europe. But there is a slight difference between the two terms. MEMS is microelectromechnical system which is more restrictive having a mechanical and an electrical part. Microsystem does not necessarily have a mechanical component (mechanically active - movable). A set of mixing channels for microfluidics could be considered a microsystem but it would be less a microelectromechanical system. Twisp (talk) 20:17, 24 April 2008 (UTC)

mems

i'm a research student . i have the following questions 1.what is the scope of mems in electrical drives and what is the new problem 2. what are the companies doing with this mems —Preceding unsigned comment added by 219.64.116.138 (talk) 13:33, 29 May 2008 (UTC)

Please consult with your professor/advisor for the information that you seek if you are attempting to leverage the article for your research. If that is the case, I would highly advise against it. Additionally, there is already some examples indicated in the article of what you are looking for from what I can decipher from your questions. If you are trying to suggest that those items would benefit the article please clearly indicate that. Also, please realize the discussion page is NOT a forum. —Preceding unsigned comment added by 63.161.86.254 (talk) 14:56, 13 June 2008 (UTC)

What about limitations of current fabrication technologies??

We see some positive discussion, but very little regarding the problematic limitation of current fabrication techniques. For example, silicon-based fab methods are slow and expensive to develop devices with. What's more, they do not allow for many geometries that are desirable, forcing developers to "devolve" ideal device concepts to make the compatible with existing fab techniques. i think that there should be discussion on the major fab techniques regarding their limits.

there should also be discussion on desirable criteria of future microfab techniques, even if the criteria is only theoretical in nature..it at least informs people what the industry would like to see, and what would be beneficial to MEMS. —Preceding unsigned comment added by 97.97.44.4 (talk) 16:08, 12 June 2008 (UTC)

See also

See also section still seems a little long, even after I removed some entries that were just companies that made MEMS (and seemed almost like adverts).

To Do

• Add a ==History== section
• Add a section on difficulties of design and manufacture
• Reorganize?
• Image suggestion

It would be great if some images could be added. You can see some examples on Google. I invite you to add an image if you find one on commons. Wikispaghetti (talk) 20:20, 21 July 2013 (UTC)

Since we are talking about images: At the end of the section "Positive and Negative Photoresist" is a "Figure below" mentioned but not shown. — Preceding unsigned comment added by 88.74.63.197 (talk) 16:47, 11 February 2015 (UTC)

The editor who inserted that seems to have forgotten to add the image. No such image has ever been in the article. I have removed the sentence. SpinningSpark 22:53, 11 February 2015 (UTC)

Actually, the whole contribution was a copyvio, which explains the failure to include the diagram. I have deleted it, please do not reinstate. SpinningSpark 23:22, 11 February 2015 (UTC)

Do we need to have the mite?

It's a very impressive picture, but the main focus of the picture is the mite. Also, I'm sure that I'm not the only one who is grossed out by the thought of these little buggers. I understand Wikipedia is not supposed to be censored, but I didn't come to this article to see pictures of mites. It would be like if the main picture for the couch article was of a naked man sitting on a couch. KenFehling (talk) 07:54, 6 April 2009 (UTC)

I think it is nice to see how small the parts are. But the text definitely needs images of MEMS parts themselves. Wikispaghetti (talk) 20:20, 21 July 2013 (UTC)

Correct grammar in the main definition

“Microelectromechanical systems (MEMS) (<..>) is the technology of the very small, and merges at the nano-scale into nanoelectromechanical systems (NEMS) and nanotechnology.” Very small what?

Industry structure section is misleading

"The global market for micro-electromechanical systems, which includes products such as automobile airbag systems, display systems and inkjet cartridges totaled $40 billion in 2006 according to Global MEMS/Microsystems Markets and Opportunities, a research report from SEMI and Yole Developpement and is forecasted to reach $72 billion by 2011.[12]"

The impression this sentence gives is that the MEMS devices themselves are a $40 billion market and expected to be a $72 billion market by 2011. The actual forecast as of July 2010 is that MEMS devices will be a $16 billion market by 2015, and were,in 2009,a $6.5 billion market. The difference is between the price of an inkjet printer cartridge or an airbag and the cost of the MEMS device. Walt Sciencewriter (talk) 20:06, 22 July 2010 (UTC)

Self replication?

Will MEMS devices be capable of self replication? —Preceding unsigned comment added by 173.58.64.64 (talk) 19:10, 16 September 2010 (UTC)

self replication is a different animal entirely. that said, biomechanical systems exist in the micro and nano scale so it seems entirely plausible. personal, I would expect to see a cellular biology approach were a MEMS/NEMS scale device can navigation the interstitial space and is accepted by and works in concert with the cell's bio-organelles before we achieve fully autonomous self-replication. Steven Kirkland ^(talk) 13:24, 27 August 2021 (UTC)

Plagerism?

I note that several sequences are replicated here http://oece.usst.edu.cn/Nanotechnology/show.asp?id=81

I'm not sure how to proceed to check this source and qualify WP:PLAG any suggestions? --Seanwong (talk) 13:26, 20 December 2011 (UTC)

I can't tell who copied from whom - there is no date stamp on that page. Materialscientist (talk) 13:32, 20 December 2011 (UTC)

That page is now dead, but it was archived in 2012 by the Wayback Machine. I think it is highly unlikely that this is a copyvio on the part of Wikipedia. Although the copyright notice on the site says "copyright 2003-2011, University of Shanghai for Science and Technology" there is no evidence in any archive that I can find that the page even existed before 2011 and I suspect that that was just a general notice on all pages of the site. Against that, the corresponding passages started in the Wikipedia article in 2007 with a noticeably different wording and slowly evolved to the current wording over a number of years. Hence, my surmise is that it is oece.usst.edu.cn that is (or was) infringing the copyright of Wikipedia editors, not the other way round. SpinningSpark 14:26, 1 March 2014 (UTC)

Introduction: MEMS size

MEMS are made up of components between 1 to 100 micrometres in size (i.e. 0.001 to 0.1 mm), and MEMS devices generally range in size from 20 micrometres (20 millionths of a metre) to a millimetre (i.e. 0.02 to 1.0 mm).

question from an old-fashion mechanical engineer: what is size in this context? I am thinking about a kind of characteristic dimension or some sort of average among the main dimensions of a 3D solid but I guess that is not the case. I am reading people talking about a critical dimension in MEMS. In this case, a link to http://en.wikipedia.org/wiki/Critical_dimension would be helpful but that page doesn't contain a paragraph or in-line reference to MEMS.--87.2.200.94 (talk) 08:07, 30 September 2014 (UTC)

I don't think it's anything that definite. It just means the outside dimensions of a mechanical component, cantilever for instance. These size ranges are quite arbitrary, the real distinction is that it ceases to MEMS and turns into nanotechnology at a size when the component can no longer be analyzed in terms of its mechanical properties alone, for instance, when surface chemistry starts to be important.

In truth, I don't really understant the page you linked. I don't think it has anything to do with MEMS. Critical dimension in a MEMS context usually means the minimum feature size that can be achieved with photolithography or whatever manufacturing process is being used. SpinningSpark 08:52, 30 September 2014 (UTC)

Thanks for your quick feedback. What you say is clear but something makes me wonder. See https://www.mems-exchange.org/MEMS/what-is.html or http://electroiq.com/blog/2013/10/mems-devices-for-biomedical-applications/. They say: The critical physical dimensions of MEMS devices can vary from well below one micron on the lower end of the dimensional spectrum, all the way to several millimeters.; they seem reliable sources. So, critical dimensions' range is the same as overall outside dimensions'? Here, http://help.autodesk.com/view/MFIWS/2015/ENU/?guid=GUID-71C8C28A-6591-4FEF-97EF-E6E71BE2428B, they give a good definition of critical dimensions in non-MEMS mechanical components: By critical dimensions we mean those dimensions where the part specifications demand that the indicated tolerances be met. It is not as much related to the manufacturing process as in MEMS's, but it is still a kind of constraint.

About outside dimensions of a mechanical component: the size of the article must be a characteristic dimension of a component or the whole system; take a cylinder, you may choose diameter or height. In your cantilever example, I may focus on one of the 3 dimensions of a rectangular parallelepiped. If I pick up the shortest, we are back to critical dimensions. So, I guess I must point to the longest?--87.2.200.94 (talk) 10:12, 30 September 2014 (UTC)

Well that makes a lot more sense than the Wikipedia article you linked. Which dimensions are critical in that sense depends on the application of the component. For a cylydrical resonator, both the diameter and the height are critical to setting the resonant frequency. The same can be said for a cantilever used as a resonator, but used as part of an actuator presumably only the length is critical. SpinningSpark 10:44, 30 September 2014 (UTC)

See this book for a description of the use of the term to mean minimum printing dimension. SpinningSpark 10:50, 30 September 2014 (UTC)

Physics

Hi, it is physically incorrect to say: "At these size scales, the standard constructs of classical physics are not always useful. Because of the large surface area to volume ratio of MEMS, surface effects such as electrostatics and wetting dominate over volume effects such as inertia or thermal mass"

Namely, by saying "classical physics" one thinks of a quantum-mechanical physics (i.e., non-classical). But what follows in the next sentence is "electrostatics and wetting", which is still a classical physics.

I suggest to to rewrite "At these size scales, the standard constructs of classical physics are not always useful. Because of the large surface area to volume ratio of MEMS, surface effects such as electrostatics and wetting dominate over volume effects such as inertia or thermal mass" with "At these size scales, in addition to the Newtonian mechanics one also has to account for forces produced by electromagnetism (e.g., electrostatic charges, magnetic moments, etc.), fluid dynamics (e.g., surface tension, viscosity, etc.) and of other sources."

In addition, from physical point of view, "electrostatics" and "wetting" belong to different logical classes. Thus, it is like making a comparison between length and weight.

Hope it will help!

Alex,

[email protected] — Preceding unsigned comment added by 2001:569:79C0:3100:384A:600:9D27:C37C (talk) 03:07, 14 October 2016 (UTC)

I don't think this is a bad point but it seems to lose the fact that this happens because of the high area/volume ratio. Pinkbeast (talk) 17:05, 17 October 2016 (UTC)

I agree, the second sentence is fine, the problems are all in the first sentence. It would be better to say "are not always sufficient" rather than "not always useful", I'm going to change that after posting this. More difficult, the IP would change "classical physics" to "Newtonian mechanics", but I don't think Newtonian mechanics would cover thermal mass so that doesn't quite work. SpinningSpark 18:04, 17 October 2016 (UTC)

I just tweeked the lede to address this issue and "Introduction: MEMS size" thread above. Sparkie82 (t•c) 20:45, 27 January 2017 (UTC)

Merge proposal

It appears that microsystem is a WP:FORK for this article. The two cover the same territory, the former is a stub with inadequate citations, and the lede indicates that they are synonyms. Any objections? — Ƶ§œš¹ _{[lɛts b̥iː pʰəˈlaɪˀt]} 20:02, 14 March 2019 (UTC)

 Done Feel free to revise as it suits you. — Ƶ§œš¹ _{[lɛts b̥iː pʰəˈlaɪˀt]} 18:05, 14 April 2019 (UTC)

Ken Gabriel

Ken Gabriel, real name Kaigham Gabriel seemed to have invented Mems and is considered the father of MEMS.[6],[7], [8] scope_creep^Talk 11:52, 16 March 2019 (UTC)

Issues and Concerns

Is there a need to have a section to discuss this aspect of MEMS, e.g. the issue of Helium affecting the frequency of oscillator chips?

There may be other issues or concerns which would need to be considered before selecting this technology as an engineering solution. — Preceding unsigned comment added by 2604:2D80:B381:0:757A:CAD8:2BB8:4944 (talk) 21:31, 19 May 2022 (UTC)