One of the things that has generally been under the radar in earth science has been the general retreat from equipment making. Basically, devices are generally good enough for the work we want and so the changes being made, such as they are, are not game changers. With the focusing of portable equipment into centralized equipment facilities, there has been a standardization on specific types of equipment. While this overall has been a plus for the community as investigators can check out equipment familiar to them, it has discouraged the kind of tinkering that individual research groups used to conduct when they all had to make their own tools. Although there have been moments when some dramatically different kind of sensor seemed possible, pretty much what we have today only differs in small respects from what we had 30 years ago.
So the Nature paper suggesting that a tiny gravimeter that possibly could be cheaply manufactured is kind of exciting and unexpected (see also the BBC News story). This builds off of the kinds of accelerometer found in many smartphones and has, in the lab at least, demonstrated the ability to measure tides into the microgal level (about one billionth of the pull of gravity). If the device can be made portable, it would replace instruments costing upwards of $30,000 that require substantial power and need to be treated nicely. Right now gravity surveys are rather tedious affairs; if this gravimeter shows real stability over long time periods, it could allow for widespread measurements of changes in gravity due to changes in water storage, snowpack, and even tectonic changes.