At the beginning of the Covid-19 pandemic, Apple engineers embarked on a rare collaboration with Google. The goal was to build a system that could track individual interactions across an entire population, in an effort to get a head start on isolating potentially infectious carriers of a disease that, as the world was discovering, could be spread by asymptomatic patients. Delivered at breakneck pace, the resulting exposure notification tool has yet to prove its worth. The NHS Covid-19 app uses it, as do others around the world. But lockdowns make interactions rare, limiting the tool's usefulness, while in a country with uncontrolled spread, it isn't powerful enough to keep the R number low. In the Goldilocks zone, when conditions are just right, it could save lives.

Greece and Rome were, like many areas of the ancient world, multilingual, and so needed both translators and interpreters. My own thesis into English to Welsh translation – due to be published later this year – shows that a translator working to correct the output from machine translation makes for higher productivity and quicker translation. Well over 350,000 people speak Welsh every day, while local authorities across the UK are also translating into numerous other languages. Today, machine translation can create rough drafts of relatively simple language, and research shows that correcting this draft is usually more efficient than translation from scratch by a human.

Imagine a world where everyone can perfectly understand each other. Language is translated as we speak, and awkward moments of trying to be understood are a thing of the past. This elusive idea is something that developers have been chasing for years. Free tools like Google Translate – which is used to translate over 100 billion words a day – along with other apps and hardware that claim to translate foreign languages as they are spoken are now available, but something is still missing. Yes, you can now buy earpiece technology reminiscent of the Hitchiker's Guide to the Galaxy babel fish – a bit of kit which claims to so a similar job to that a university-trained, professionally-experienced, multilingual translator – but it's really not that simple.

Another option is to use more robust cells as actuators. Here at Case Western Reserve University, we've recently begun to investigate this possibility by turning to the hardy marine sea slug Aplysia californica. Since A. californica lives in the intertidal region, it can experience big changes in temperature and environmental salinity over the course of a day. When the tide goes out, the sea slugs can get trapped in tide pools. As the sun beats down, water can evaporate and the temperature will rise.