Hard tech I define as things for which there is no guarantee that the technology is physically possible.

So not just "hard" in the sense of being physical -- building a LED light bulb isn't "hard tech" to me because the outcomes are comparatively very predictable and you can essentially completely design an end product with no physical prototype if you had to (though QC is another story).

On the other hand, making a new LED die technology with a new semiconductor material is "hard tech", because it may just not work for reasons that are impossible to anticipate. But that would certainly require a wet lab.

Even for sophisticated electronics projects, between datasheets, spice, circuithub, etc I've never felt that a project could just fail because it's literally impossible, but that is absolutely a potential outcome for a project I'd call hard tech.

Same for mechanical design, the projects might be astronomically challenging, but usually whether it's possible can be predicted with extremely high accuracy if you've built a SolidWorks model and understand adequately how to evaluate things like material strength, creep, machining limitations, thermal expansion and so on. But these are all extremely well understood things.

I'd also consider electronics or mechanical projects to be in the same category as software in that it is fairly easy to operate out of your house (or using more commonly available coworking spaces with machine shops, like the Artisan Asylum or Greentown) until you've figured out whether your prototypes will work.

So, yes, I mean wet lab facilities when I think of "hard tech". Stuff that doesn't scale and which no amount of clever thinking can guarantee will ever be possible to accomplish. For my project, for instance, it took a solid year just to prove that what I wanted to do wasn't possible and there was just no way I (or any of the folks who reviewed the idea before I did it) could know for sure without putting in the effort.

This heuristic might be a little limited in edge cases, but this is what I was meaning.

I'll also add that I am thinking of pre-employee companies. If you have employees, you have some kind of funding already. I'm talking about that stage where if it were a startup you'd be creating your MVP to show investors to get seed funding.

That is absolutely impossible for I suspect most "hard tech" companies, where getting to a MVP will require years of effort to prove conclusively the value proposition (i.e. will it work, and what does the real value proposition look like?). That effort could easily be done solo at low cost -- if the equipment and facilities were free or nearly free.

Hopefully that clarifies! I wasn't aware that people considered things like Bolt to be hard tech, honestly. Is this common usage to just call anything that's not literally computer code "hard tech"? Because I think that definitely groups companies together that really don't make any sense to think about as being similar.

Iterating on electronics hardware may take months and cost perhaps tens of thousands of dollars. Iterating on new polymer coatings to encapsulate electronics in the bloodstream takes years. It seems misleading and less useful to pretend that the two are particularly similar.