Yeah, I'm a bit disillusioned having watched this technology for years. Piezoelectric speakers (and even voice coil driven larger displays) have been around in

Yeah, I'm a bit disillusioned having watched this technology for years. Piezoelectric speakers (and even voice coil driven larger displays) have been around in laptops since the mid 2000s. That's 20 years. I think the Sony Acoustic Surface you're talking about was based on voice coils when it was introduced in 2017, but I wasn't involved in it. It could be piezo now... certainly 50-60in surface would make larger displacements (lower frequency at higher volume) competitive with regular speakers possible. There are a lot of challenges with piezos in terms of cost, limited motion, and voltage (usually higher than 100V) that are difficult to make up for with thickness. Their performance (linearity) also seems to suffer quite a bit for any significant driving range. Generally, the bending moment (direct displacement is usually limited to a few % which is micrometers) is most useful for larger and thinner surfaces since deflection is nominally length^3/thick^3 or worse with strain. The haptics are just as challenging (and you often don't want to hear them!) for similar reasons and usually can't be localized. Touch position sensing is possible but tends to be very sensitive to mounting, wear, and dirt. There are really cool technologies developed, but there's a reason you don't see many in mass production even after 20 years. You have to have a VERY reliable and useful feature to get integrated into UI and the OS.