Tag Archives: technology news

The swarm is near: get ready for the flying microbots

Imagine a swarm of insect-sized robots capable of recording criminals for the authorities undetected or searching for survivors caught in the ruins of unstable buildings. Researchers worldwide have been quietly working toward this but have been unable to power these miniature machines — until now.

A 0.16 g microscale robot that is powered by a muscle-like soft actuator. Credit: Ren et al (2022).

Engineers from MIT have developed powerful micro-drones that can zip around with bug-like agility, which could eventually perform these tasks. Their paper in the journal Advanced Materials describes a new form of synthetic muscle (known as an actuator) that converts energy sources into motion to power these devices and enable them to move around. Their new fabrication technique produces artificial muscles, which dramatically extend the lifespan of the microbot while increasing its performance and the amount it can carry.  

In an interview with Tech Xplore, Dr. Kevin Chen, senior author of the paper, explained that they have big plans for this type of robot:

“Our group has a long-term vision of creating a swarm of insect-like robots that can perform complex tasks such as assisted pollination and collective search-and-rescue. Since three years ago, we have been working on developing aerial robots that are driven by muscle-like soft actuators.”

Soft artificial muscles contract like the real thing

Your run-of-the-mill drone uses rigid actuators to fly as these can supply more voltage or power to make them move, but robots on this miniature scale couldn’t carry such a heavy power supply. So-called ‘soft’ actuators are a far better solution as they’re far lighter than their rigid counterparts.

In their previous research, the team engineered microbots that could perform acrobatic movements mid-air and quickly recover after colliding with objects. But despite these promising results, the soft actuators underpinning these systems required more electricity than could be supplied, meaning an external power supply had to be used to propel the devices.

“To fly without wires, the soft actuator needs to operate at a lower voltage,” Chen explained. “Therefore, the main goal of our recent study was to reduce the operating voltage.”

In this case, the device would need a soft actuator with a large surface area to produce enough power. However, it would also need to be lightweight so a micromachine could lift it.

To achieve this, the group elected for soft dielectric elastomer actuators (DEAs) made from layers of a flexible, rubber-like solid known as an elastomer whose polymer chains are held together by relatively weak bonds – permitting it to stretch under stress.

The DEAs used in the study consists of a long piece of elastomer that is only 10 micrometers thick (roughly the same diameter as a red blood cell) sandwiched between a pair of electrodes. These, in turn, are wound into a 20-layered ‘tootsie roll’ to expand the surface area and create a ‘power-dense’ muscle that deforms when a current is applied, similar to how human and animal muscles contract. In this case, the contraction causes the microbot’s wings to flap rapidly.

A microbot that acts and senses like an insect

A microscale soft robot lands on a flower. Credit: Ren et al (2022).

The result is an artificial muscle that forms the compact body of a robust microrobot that can carry nearly three times its weight (despite weighing less than one-quarter of a penny). Most notably, it can operate with 75% lower voltage than other versions while carrying 80% more payload.

They also demonstrated a 20-second hovering flight, which Chen says is the longest recorded by a sub-gram robot with the actuator still working smoothly after 2 million cycles – far outpacing the lifespan of other models.

“This small actuator oscillates 400 times every second, and its motion drives a pair of flapping wings, which generate lift force and allow the robot to fly,” Chen said. “Compared to other small flying robots, our soft robot has the unique advantage of being robust and agile. It can collide with obstacles during flight and recover and it can make a 360 degree turn within 0.16 seconds.”

The DEA-based design introduced by the team could soon pave the way for microbots that work using untethered batteries. For example, it could inspire the creation of functional robots that blend into our environment and everyday lives, including those that mimic dragonflies or hummingbirds.

The researchers add:

“We further demonstrated open-loop takeoff, passively stable ascending flight, and closed-loop hovering flights in these robots. Not only are they resilient against collisions with nearby obstacles, they can also sense these impact events. This work shows soft robots can be agile, robust, and controllable, which are important for developing next generation of soft robots for diverse applications such as environmental exploration and manipulation.”

And while they’re thrilled about producing workable flying microbots, they hope to reduce the DEA thickness to only 1 micrometer, which would open the door to many more applications for these insect-sized robots.

Source: MIT

Alexandria in the Ether

The vision must have been — in its own way — almost terrifying: every book ever written, every thought ever committed to writing, all the knowledge in the world, stored within the walls of a single, gleaming edifice.  Experts agree that what we know today about the Royal Library at Alexandria is half history, half myth.  Demetrius of Phaleron, the Greek statesman and orator, is said to have conceived of the Temple of the Muses and its legendary bibiliothekai while living in exile under the protection of Ptolemy I Soter of Alexandria.  The library is believed to have been destroyed by a succession of wars and fires — one of them famously ordered by Julius Caesar.

People have since built libraries and universities after this ancient paradigm in every major city in every part of the world.  Many of these modern public libraries and places of learning house collections that are nothing less than spectacular, but none come close to the mythic vision of the original.

New technology for an ancient vision

Today, the establishment of a truly universal library is within our grasp.  The technology is certainly available.   The worldwide web already makes massive stores of information accessible to anyone connected to the network, and e-mail and RingCentral VOIP services allow people to communicate and exchange documents with no more than a few clicks of the mouse.  All that needs to be done, in fact, is to digitize the books already stored in the world’s great libraries.

In 2010, Harvard’s Berkman Center for Internet and Society proposed to do just that, announcing a massive and ambitious project to coordinate the Digital Public Library of America (DPLA).  As originally conceived, the DPLA website would have offered online access to the vast and diverse collection of books stored in major libraries, creating a free, open and democratic online library in the process.  But the visionary endeavor has since been bogged down by legal issues, frustrating scholars, observers, and the many millions who would have benefited from the project’s completion.

Legal impediments

The  DPLA’s legal troubles stem from copyright restrictions which disallow most books published over the last 100 years in online databases.  Apparently, these books have yet to enter the public domain.  This is after recent legislative measures introduced amendments to relevant copyright laws.  “Early copyright legislation guaranteed that no book would remain under private control for very long,” according to Nicholas Carr in an article written for Technology Review.  Carr says this changed beginning in the 1970s, when — under pressure from Hollywood and various entertainment companies — US Congress passed a series of bills that dramatically lengthened the term of copyright for books written throughout most of the last century.

“Some scholars believe copyright restrictions will frustrate any attempt to create a universal online library unless Congress changes the law,” Carr writes.

A dream on hold

The democratization of knowledge is among the most enduring aspirations of mankind.  For centuries, access to education and knowledge was bestowed only on a selected few.  These few, favored by birth or wealth, would have continued their now discredited system had it not been for the labors of those took up the banner of reform, arguing, in turn, that all men have the right to learn, and in learning become free.  With the internet, that dream has come within tantalizing reach of people in practically every part of the planet; the worldwide web lends itself easily to the sharing of knowledge on a broad, sweeping and inclusive scale:  a farmer from Kenya or a cabbie from Brooklyn gets no less Google or Wikipedia than — say — Bill Gates.  And that is a good thing.  Many are hopeful that America’s best libraries will one day be allowed to expand on this spirit of equity.

Until that day comes, however, it appears the DPLA will have to put on hold the fulfillment of a dream that humanity has cherished for well over 2,000 years.