If you’re talking about a hot plate, that’s not the same thing. I don’t want a hot plate next to me while I work. Plus they’re inefficient.
They have! Back in 1969, there was a short lived option for Chevys that would spray “Liquid Tire Chain” onto your tires (from spray cans mounted in the trunk) with the push of a button. Liquid Tire Chain was basically rosin, and it worked fine, but was discontinued quickly.
I had this in 1963 or so.In a small Renault. It was called the “city horn” and the “countryside horn”–one was higher and louder than the other.
Well, actually, it was my parents who had it–I was in kindergarten. (So don’t ask me details 'bout the car. 
)
And I thought my Dad was the greatest entertainer in the world! He could play a melody: 3 or 4 quick toots on the horn at alternating pitches.
That’s a hot plate.
My idea is the heating element is in the bottom of the mug itself, and is powered by magnetic induction from the electric coaster. So, the coaster itself is not hot, and would save electricity when the mug is not on its surface. Nor would it be any sort of hazard.
If you have a rechargeable electric toothbrush, it’s the same idea. It recharges through magnetic induction, when you set it on its base. Except, instead of recharging a battery, the element at the base of the mug would heat up.
I’d rather not keep a hot surface next to me most of the day. Or have to remember to shut it off if I bring my mug into a meeting, etc.
My design is even better. The heating element is at the end of a slender copper tube that hugs the curve of your cup. Why? You fill your cup with water, attach the tube to the clamping cover that holds the funnel, the heater heats up the water, forcing it up the tube into the funnel where it brews with the coffee until the heater switches to low power, drawing the fresh coffee down into your cup. This is called the “vacuum brewing” process, which has been around for centuries and makes absolutely the best tasting coffee. No one has made a single-in-cup vacuum brewer, though, AFAIK.
Sounds cool. But my design is not intended to brew the coffee, just to keep it hot. Though I suppose yours could be both.
That’s a great idea! If you could just lean forward, I have to get some measurements of your neck for the guillotine, er, -I mean medal of freedom. To go around your neck.
An invention I thought of before canned sunscreen: a sunscreen shower. Attach it to the nozzle of a shower, like those weed sprays. As you’re taking the shower, you are getting sunscreen evenly applied.
Nair for the face. Never shave.
Helper monkey making fresh coffee throughout the day, serving it as well. Bringing a cookie now and again.
There’s also Ember, a heated coffee mug which can be yours for $80: Ember Mug² - Heated Coffee Mug, Smart Mug - Ember (RED) Mug - Ember®
What’s wrong with just dropping a piece of radioactive waste in your coffee mug?
I tried that for a while, but I had to chew so many of those Radiads antactinides afterwards (they are expensive, taste terrible and cannot be just swallowed) that my teeth became saturated with [sup]296[/sup]Oganesson and glowed in the dark for almost a month after I stopped.
Hot coffee in the morning, night light after dark – win, win!
Squeee!
This is what I’m talking about, though it has an on-board battery that is used to power the heating elements, and a microprocessor to talk to an app. But it looks like it uses the coaster idea (which I had in 2010) to power everything in the mug. I might order it… maybe after the cost comes down…
I invent things all the time mostly for my own use or just for fun but I think my most brilliant idea could be worth billions of dollars if I could pull it off. Creating a platform for a social media site that allows virtually anyone and everyone to become part of a collaboration. I have actually played with this for at least a decade or more and it continued to evolve until about 2 years ago. It is mostly based on a hierarchy of human emotions and needs but also deals heavily on the financial aspects. The fate of entire program rests in my ability to create a fictional movie script or better yet a pilot followed up by a series that would introduce this to a public that has no clue as to what it is about or how it might work.
When I was in electronics school, I designed a car horn that was really a sampler. The idea was, you’d have different samples of people saying things that would be played back when you pressed the horn button. You could record your own samples.
In other words, it would yell at people to get out of the way.
The streetcars in Toronto have this, at least the old ones.
For cars and snow, I am wondering whether something g coarser than sand would be better.
A debit card operated barbecue for apt complexes, either propane or natural gas. The gas would be metered so the cheap ass landlords could make a little profit off of it.
Semi permanent tattoo ink. It would last a few years, not a lifetime. It would degrade slowly and safely. But that way you can choose a tattoo that would last longer than a stick on or henna, but not FOREVER. Perfect for people who change their minds. No lasers - just eventual fading.