Why drones should learn from nature

My aunt who lives in the Himalayas, casually mentioned that drones would drop medicines at her home because people in her remote village had no access to medicines. This was not the first time I heard about the role of drones in telemedicine, but it was heart-warming to know that drones are covering some of the hard-to-reach places.

Over the past many years, drones are becoming commonplace, now delivering supplies, doing emergency medical care, conducting surveys, restoration work and so forth. Like large dragonflies, they buzz overhead at weddings and concerts. The more ambitious we become with our drones, the more efficiency we require in these unmanned aerial vehicles (UAVs).

The drones’ lightweight and pocket-sized form factor puts a constraint on their payload, memory, and computation. They cannot use bulky sensors. The on-board electronics can use merely 5-10 per cent of battery power.

Scientists are looking at ways to improve drones. They are taking inspiration from flying creatures sharing the airspace with drones. Birds and insects use a flight system that evolved over 100 million years. Drones have a long way to go before they become as efficient as birds and insects that inspired the creation of drones in the first place. Humans have been taking inspiration from nature’s design of flying creatures for the longest time.

In Greek mythology, Icarius got himself a pair of wings that were fabricated with wax by his father Daedalus. Legend goes that Icarius flew too close to the Sun, and the wax promptly melted, thus resulting in a disastrous end to his flying mission. In the 16th century, Leonardo Da Vinci tried to decode and design the system of birds’ flight. He named it ornithopter. This was an early recognition of nature’s time-tested designs that are both efficient and enduring. It is hardly surprising that Wright brothers were birders before they took that historic flight. They incorporated maneuvers of soaring birds into their design.

Despite all our efforts, birds fly far more efficiently than our UAVs. The hummingbird has a large chest bone to support the wing muscles that power the flapping of wings at a high frequency. When hovering, hummingbirds flap their wings in figure 8 while their short arm bone does a ‘wrist flick’. This design was incorporated into the drone operated by the US defense agency, DARPA. Bees can classify information about objects and understand cause and effect.

Birds and insects can efficiently handle multiple concurrent processes in flight. They have a high-level of perception. Multitasking is second nature for birds, which is not something drones are good at, especially the commercial off-the-shelf ones. If a drone went on a mission to drop seeds in the forest, it cannot do targeted spraying of medicine in the same mission. Scientists are mimicking the human brain where specific tasks are mapped to separate areas. In drones, scientists are experimenting with the use of two microcontroller units (MCUs), for separate tasks that do not require interactions, such as exploration of an unknown mission area and object detection to avoid collision simultaneously. This would improve a drone’s multitasking abilities.

A study by Lund University in Sweden shows that when flying slowly, curiously enough, birds flap their wings more horizontally in an energy intensive manner. Scientists believe that they do so to create a massive force to propel themselves and remain high up in the air. Drones with flapping wings is a possibility in future.

Scientists are studying owls that fly in pin-drop silence because of the structure of their wings. The primary feathers have a fringe that gently funnel air over the wings to muffle the sound. With the number of drones increasing in our airspace in future, we will need quieter technologies for UAVs. Drones are flying like bats using echolocation to avoid collision and perching like falcons for a soft landing.

Human-created technology is nascent compared to the millions of years of slow incremental innovation by nature. Biomimicry has grown popular as we try to understand why and how natural systems operate the way they do. While designing a flying object, Leonardo da Vinci focused on birds’ overall form and so included flapping wings. Over the years, the design did not help those who tried to use it as a template to build an aircraft. The Wright brothers instead chose to observe gliding birds, which was useful in relation to the limited aeronautical knowhow at the time, Today, scientists are evaluating flapping wings for drones.

Scientists have so far initiated research on what they observe in nature. We need to look at the underlying first principles that power biological systems and conserve resources. We must use bottom-up engineering to pay attention to the little details that matter. Biological systems function brilliantly at nano-scale, which is perfect for tiny drones. Therefore, Innovation at nano-scale will effectively move the needle for drones.

(Shalini Verma is a serial entrepreneur.)

• Opinion