Dengue fever, malaria, Zika, West Nile virus and other mosquito-borne diseases may have finally met their match in crowded cities across the tropics. An unmanned, subterranean, robotic probe dispatched into the sewers of Kaohsiung City, Taiwan has proven lethally effective at locating the hidden pools of stagnant water where mosquitos breed. The sewer robot searches, so Taiwan's exterminators can destroy it. Researchers with Taiwan's National Mosquito-Borne Diseases Control Research Center found that their robotic hunter helped dramatically curb the city's mosquito population -- dropping the number of blood-sucking bugs by nearly 70 percent. Researchers with Taiwan's National Mosquito-Borne Diseases Control Research Center found that their robotic hunter helped dramatically curb the city's mosquito population, dropping the number of blood-sucking bugs by nearly 70 percent, based on their'gravitrap index' Researchers designed an unmanned ground vehicle (top) to scour cracks and crevices deep in the sewers of Kaohsiung.

Snaking beneath our feet, all across America, are hundreds of thousands of miles of dark, dank tunnels. These channels for wastewater and storm water are, according to those who explore them for a living, home to all manner of hazards, including creatures (rats and alligators), obstructions ("fatbergs" and mineral deposits), and poison gasses concentrated enough to eat through concrete. Keeping those aging, subterranean arteries from spilling their toxic contents is enormously complicated and costs tens of billions of dollars a year more than U.S. cities can afford to pay. Which is why cities and the service contractors they rely on are deploying an array of technological tools that boast the potential to explore, diagnose and repair sewer systems in new and more affordable ways.

A four-legged robot that inspects concrete can walk through underground sewage tunnels and detect when they need repairing. Hendrik Kolvenbach at the Swiss Federal Institute of Technology (ETH Zurich) in Switzerland and his colleagues have developed a robot that scratches one of its legs against concrete to determine the condition it is in. The robot is waterproof and it can wade through water and climb over obstacles. Because many modern sewage systems were built decades ago, constant underground monitoring is needed to prevent major leaks.

Swarms of floating robots could help map underground pipe networks and detect leaks and blockages in plumbing. Peter Baltus at Eindhoven University of Technology in the Netherlands and his colleagues have developed golf ball-sized sensors that can collect information as they float through pipes. Each robot contains a microprocessor, sensor, memory boards and a battery. They can be programmed to detect sound, temperature, pressure, acceleration, rotation and magnetic fields. To save power, a sensor can be activated by a sudden change in conditions, such as hissing sounds associated with water escaping, or increased rotation, which could be a sign of turbulent water flow.

There is great enthusiasm for the smart city concept. Integration of autonomous vehicles, drones and networked communications are expected to manage congestion, lead to fewer accidents, reduce pollution and enhance quality of life. The smart city was a major theme at the 2018 Consumer Electronics Show (#CES2018), hosted by the Consumer Technology Association. Will smart cities be vibrant bastions of competitive private free enterprise and innovative new networks of communication that simultaneously respect individuals' privacy? Or are planners on a path to setting up mega public utilities and administered cartelization, and compulsory information collection?

I've written a number of times previously about the drive towards smarter cities, with the Internet of Things used to monitor key infrastructure and even provide real-time repairs. One interesting project is taking place in the sewers beneath the American city of Cincinnati. The Metropolitan Sewer District of Greater Cincinnati (MSD) aims to develop a "smart sewer" that reduces the overflow into the cities rivers and creeks. MIT researchers are working on a similar approach, albeit their aim is to reduce leaks that result in roughly 20% of global water supplies being lost during transportation. Their system consists of a rubbery robot that looks a little bit like a badminton shuttlecock. The device is inserted into the water system, and then is carried along with the flow of water, measuring and logging as it goes.