Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design Subject: Re: MIT 3D printed key components of mass-spectrometer Date: Tue, 9 Apr 2024 01:17:21 +1000 Organization: A noiseless patient Spider Lines: 44 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Mon, 08 Apr 2024 15:17:24 +0200 (CEST) Injection-Info: dont-email.me; posting-host="9cb23bc52e0b2d1fdfba8a9347de4baf"; logging-data="3762035"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18XMDzdXSWY8koWP2/cv7IJxe9g4vbfWgk=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:npHzFEHb8+i5TImQz3BOxJugsVU= In-Reply-To: Content-Language: en-US Bytes: 3036 On 9/04/2024 12:28 am, John Larkin wrote: > On Mon, 8 Apr 2024 10:23:24 +0100, Martin Brown > <'''newspam'''@nonad.co.uk> wrote: > >> On 08/04/2024 05:47, Jan Panteltje wrote: >>> Researchers 3D print key components for a point-of-care mass spectrometer >>> https://www.sciencedaily.com/releases/2024/04/240404113429.htm >>> pdf: >>> https://pubs.acs.org/doi/10.1021/jasms.3c00409 >>> >>> Massachusetts Institute of Technology >>> Summary: >>> Researchers 3D printed a miniature ionizer, a key component of a mass spectrometer. Their device could someday enable an affordable, in-home mass spectrometer for health monitoring. >> >> It is complete nonsense. Making the hard vacuum needed for ions to move >> freely in mass spectrometry and sample handling to introduce the sample >> into the unit without losing vacuum are fundamentals that won't go away. >> >> The closest to a quick dirt cheap MS is time of flight laser ablation if >> your sample is a solid or can be put on one. Liquid samples are really >> messy and water vapour is the bane of vacuum systems. >> >> Selective ion probes offer a much better alternative for bio samples (I >> suppose the MIT PR department has to justify its existence somehow). > > I'd expect 3D printed stuff to outgas forever. It wouldn't be much use in a mass spectrometer if it did. Out-gassing vaccuum systems always involves getting them hot for quite a while and pumping them hard. Maybe you have to laser fuse a thin layer over the entire surface while maintaining a high vaccuum. > 3D is super slow, too. I've heard of modestly complex parts taking > days to fab. The upside is that it can make things that are impossible > to machine or mold. As Phil Hobbs says, the printers are cheap so you can put a lot in parallel. The post-processing to get the outgassing down might not be so easily paralleled. -- Bill Sloman, Sydney