The 'weight loss' trend

Many early technological revolutions seeped through the world slowly, changing industries and societies over long periods of time. The first electrical grid was developed in the U.S. at the end of the 19th century, but it didn't resemble the connected networks of the 20th century. It took several decades for factories and homes to switch from steam to electric power to run machines. This transformation continued through the last century with railway electrification around the world. It is now continuing – with electrification of automobiles.

Electricity is a platform technology, capable of increasing efficiency in entire industries over a period. Steam locomotives were among the most inefficient machines ever built: around 90% of the energy in the fuel was wasted. Steam turbines improved thermal efficiency to about 35%. Diesel-electric locomotives, which combine diesel-burning with an electric motor, were a major advance over steam engines. The fully electric locomotive, running on the grid, runs at over 90% efficiency. Similarly, electric cars beat internal combustion engines comfortably on efficiency.

There were several similar platform technologies that made large-scale changes across the world. Plastics were one such invention: they reduced energy costs and increased convenience across a bunch of industries before their negative effects became apparent. The trend of miniaturisation also rewrote several industries, as devices became smaller, with shrinking geometries of microprocessors. Computers became smaller and began to sit on top of desks. Mobile phones became possible with miniaturisation of parts. Pacemakers became implantable devices. Laparoscopic and microsurgery became possible. Miniaturisation created the satellite industry. And so on in several industries.

Our Cover Story by Aditi Jain is about another trend that has been going on for a while but is now becoming transformative: lightweighting. This is technical jargon for making stuff lighter, but the word also carries connotations that are not so obvious. Lightweighting creates devices that are lighter than what we expect for a specific job. Despite their reduced weight, lightweight devices do not compromise on performance. In fact, their performance parameters often improve with the reduction of weight. Lightweight devices are designed to perform at substantially lower weights. The result of lightweighting is a worldwide revolution across several industries. It is also a key driver of sustainability, although it does come with some plastics-like complications.

The drive to reduce weight has been advancing a lot of research over the past few decades. Scientists have been researching new materials for weight reduction, and new ways of manufacturing with novel materials. Aluminium, for example, was the material of choice for lightweighting for a long time. It was superior to plastics in terms of long-term sustainability. Aluminium could be recycled any number of times without noticeable degradation in quality. The metal enabled lightweighting in its early days, before it became a noticeable and separate trend. Aluminium was not completely benign: its manufacture continued to be energy-intensive. However, recycling aluminium offers substantial cost and energy advantages. Aluminium waste collection also works better than plastic collection because of commercial viability.

Our Cover Story goes beyond aluminium and into several other trends that combine to produce a global lightweighting trend. It involves new materials, new geometries, and new methods of manufacture. It involves many industries: medical devices, aerospace, automobiles, consumer devices. Lightweight materials are diverse, and so not as easily recyclable as aluminium alloys. With the experience of plastics in mind, researchers are also designing lightweight materials for recyclability.

Unlike a few other of our Cover Stories, this one focuses almost exclusively on trends in India. Manufacturing is a key part of lightweighting, and so it cannot seep through Indian industry without domestic research and translation into manufacturing. As always, the story does not end with one cover package. It will continue in different forms through the near- and medium-term future. As you will see in future editions of the magazine, research drives lightweighting, but lightweighting also drives research that can have several spinoff benefits.

See also:

Light is right

Tiny matter, giant steps