The mechanical latching memory of an adhesive tape | Hacker News Reader

The mechanical latching memory of an adhesive tape

iopscience.iop.org

33 pointsgnabgib15 comments

If you're not aware 3M (and other companies) now sell electrically de-bondable tape. It's used in consumer device manufacture where it would otherwise be expensive (or dangerous) to remove an item for replacement like a lithium battery.

https://www.3m.com/3M/en_US/p/d/b5005605107/

Now a worn or damaged battery can be safely bonded down as it normally would with a PSA (pressure sensitive adhesive), but then after applying some 30V for a couple of minutes ions in the adhesive cause it to become easily and safely removable/repositionable.

Is this how the iphone battery replacements work by passing a 9v battery through it?

Neat! Can anyone who's worked with the stuff give us some more detail? How strong is it in practice? At 245psi tensile strength that seems about half as strong as 3M 4200 (which is not bad!). How compatible is it with various substrates? Do you need a conductive substrate on both sides to apply the release voltage? How available is it for purchase if you aren't Apple or Samsung?

I only use it to help hold together some complex assemblies when putting them together so I can't speak to it's strengths, but:

> Do you need a conductive substrate on both sides to apply the release voltage?

Yes, you attach VCC to the substrate you want to remain bonded and GND to the substrate you want to detach.

> How available is it for purchase if you aren't Apple or Samsung?

You can just call up your usual 3M distributor and request it. It's over $2,000 for a 100 meter roll so it's not something you'll usually find in stock at your local Grainger but it's not some super-secret material only available to the biggest manufacturers.

This is so cool. The discussion section [0] does a good job of explaining where this fits in, scientifically, but all I can think of is spies sending messages encoded in a piece of scotch tape.

[0] - https://iopscience.iop.org/article/10.1088/1367-2630/ae4acc#...

So I got an Incident ID and some captcha mumbo jumbo for attempting to browse that site. Apparently they don't like visitors. Feeling generous today, I decided to not inconvenience them further.

Same. Not going through a captcha for a random link.

Ironically, if you throw up road blocks for human visitors, the only ones who take the abuse will be bots.

Until last spring my bots never saw those Cloudflare CAPTCHAs despite not taking any serious evasion measures. Then all of a sudden they started getting them 100% of the time on sites I was crawling. For that particular project my webcrawler was cued by a bookmarklet, like I was picking the pages to import manually so switching to getting the data right out of the web browser got my system back on the road.

I always had the feeling that the Cloudflare CAPTCHAs discriminate in various ways, for instance I would see them much more when I was browsing on a Samsung Galaxy tablet than when I was browsing on an iPad. They disproportionately affect the disabled and I wouldn't be surprised other vulnerable populations.

If I had anything to do with it having a CAPTCHA or a GDPR popup would be an immediate WCAG fail at A level.

Good to hear I might not be paranoid, I could swear I get them far more on my linux desktop than my macbook.

I get them more on Zen (Gecko-engined) than I did on Arc (Chromium-engined). I came across this blog post about user-agent discrimination by the Vivaldi team on HN this week: https://vivaldi.com/blog/user-agent-changes/

I too detest captchas. I found the paper elsewhere:

https://arxiv.org/abs/2511.08804

the economic mechanism behind "captcha", and other verifications is to increase proffits by bleeding off relavance, a very litteral mechanical braking system, trading momentum for money, or money for momentum on a closed course. The ability to scale up friction is almost infinite and realy quite cheap, but humans are finnicky and also energetic, but the real threat to building a closed internet, is simply demand collapse. That the article is about adhesives, is a bit funny.

perhaps it's your IP/network. I'm not getting any of that

Looks like the effect was temporary, it's gone now.

Reply on news.ycombinator.com