Suppose we wanted to take advantage of modern materials, manufacturing, and pricing to make high-quality household goods. What would that be like?
How about a copper bowl? A 2mm thick copper bowl, maybe alloyed with a bit of some cheap metal to harden it, would be quite solid. Luxurious, even. What if it were a 300mm hemisphere? That’s 570 mℓ of copper. Copper’s density is almost 9 g/cc, so this would be 5 kg of copper, which would make it a rather heavy bowl. But copper only costs about US$2.20 per pound, according to the USGS (US$4.85/kg), so this is about US$25 of copper. Not a terribly cheap bowl, but that’s like US$25 for your entire life.
Even if US$25 and 5 kg is too much for a bowl, maybe it would be reasonable to copper-plate other things. Copper-plating is very cheap, and reduces infection risk, because copper kills germs. Bathtubs in particular ought to be ideal.
How about making your glasses from synthetic sapphire instead of soda-lime glass? High-purity fused aluminum oxide costs US$1440 per ton (US$1.59/kg), and about 140,000 tons of it are consumed by the US each year (as abrasives), a fraction of the worldwide use. So price and supply are not problems, but of course processing requires high temperatures and/or hard cutting tools. But the glasses would be very difficult to break or scratch and would have a totally different ring to them. Granular aluminum oxide would make a nice powder-coat enamel for materials that can resist the temperature — much like the alumina ceramic we use for spark plugs.
High temperatures probably call for molybdenum, of which the world mines some 200,000 tons per year at a price of US$14.50/kg. This leads me to believe that refractory molybdenum crucibles for growing synthetic sapphire crystals would probably only contain US$100 or so of molybdenum. However, the only sources of molybdenum I can find locally sell small reels of 110-micron molybdenum wire for manual cutting of cellphone glue, at prices like AR$35 (US$2) per meter — that’s about 100 mg (molybdenum weighs 10.3 g/cc), working out to about US$20000/kg.
(This molybdenum wire might be useful for heating elements? Molybdenum doesn’t melt until 2623°. But it oxidizes at much lower temperatures with a volatile oxide, which I suppose is to say that it catches fire.)
Pyrolytic graphite has a nice sheen to it, and although it’s brittle, it could probably be deployed advantageously to substitute for metals in many places.
Dichroic iridescent surface coatings would be a nice addition to many materials, and indeed iridescent coatings are widely available in decorations, but are currently treated as a sign of poor taste. Titanium dioxide makes the brightest colors, due to its high index of refraction.
Aerogel would be a nice substitute for fiberglass in many applications, and allows transparent high-value insulation. You could imagine the glass in the front of your oven, for example, being a silica aerogel sandwich between two plates of monocrystalline synthetic sapphire. But silica aerogel is brittle, and the powder is irritating to human skin. (It ought to be safe from silicosis by virtue of being amorphous, though.) Aerogels made from other materials, such as gelatin, might also be useful for transparent high-value insulation, even if they don’t resist such high temperatures.
Near-microscopic flexures ought to be able to make comfortable cushions, with tailored stress-strain curves, from heat-resistant, water-resistant materials — and, unlike glass fiber or ceramic fiber, it should be feasible to make them safe for human skin contact. Even a silicone or Teflon layer would aid greatly in making it possible to clean waterproof cushions.
An annoying problem I’m confronting at the moment is that available floor materials are either combustible or uncomfortably hard. An aluminum honeycomb sandwich, perhaps with aluminum mesh on the surface, could perhaps solve this problem. The aluminum has enough compliance to bounce like a wood floor, without being combustible like a wood floor. And then you can paint it with a surface treatment that reduces slipperiness and changes the color without adding too much combustibility — perhaps some kind of sand in a sodium-silicate or portland-cement binder, although that itself might suffer from cracking and flaking (perhaps with sharp, glassy edges!) if the surface is as flexible as a wood floor. Alternatively, a thin layer of plaster might work — either plaster of Paris, sand in plaster of Paris, or sand in lime. Gypsum is comfortingly soft to sit on, porous to absorb sweat, and cool without the coldness of glazed ceramics.
A bit of mica would be a nice addition to many surfaces.
Doorknobs have no need to be hollow or have sharp edges. This is not so much an issue of materials as it is of shaping. Carved soapstone would be fine.
Polycarbonate, or perhaps polycarbonate with a harder surface to resist scratching, would be a nice alternative to glass for tabletops. Candidate harder surface materials might include potassium-nitrate- hardened soda-lime glass, fused quartz, synthetic quartz crystal, and synthetic sapphire.
Garbage cans should have nonstick coatings: Teflon or silicone, for example. Moreover, organic garbage should be shredded and desiccated before it has a chance to decay, rather than dumped into a garbage can to potentially decay anaerobically. (You can add water to compost it later if you like.)
Teflon coatings would also dramatically improve zirconia kitchen knives.
There’s a lot we can do for soundproofing: isolating walls from small vibrations with the same kind of path-lengthening tricks we use for high-efficiency window frames, filling walls with fibers and foams, angling walls and ceiling to reduce standing waves, punctuating sound-absorbing walls with many small holes, and so on. None of these are novel, but they are rarely used in the home.
Sometimes it is nice to have lighting coming from small pointlike sources — when you want to bring out the sparkle of water drops or a gem, for example, or emphasize the surface profile of a sculpture you’re working on. Other times, it’s nicer to have ambient light, a desire incandescent lights were poorly fitted for. However, with LEDs, light diffuser panels, and electroluminescent materials, it’s relatively easy to put light in as many different places as you like: inside the cabinets and drawers when you open them, in a reproduction of the constellations all over your ceiling, in light diffuser panels covering the whole ceiling, inside your tabletop. Moreover, you can make the lights of whatever color you like, even changing them from moment to moment.
Teflon fabric is a really remarkable material. It cannot be stained, is undamaged by sunlight, does not decay, and is nontoxic, being entirely biologically inert.
UHMWPE is also a really remarkable material. It nearly cannot be stained, does not currently decay, and is nontoxic, but additionally it’s as strong as steel, and only slightly more compliant. This offers a number of possibilities for lightweight, free structures in furniture and the like.