Why did the gecko climb the skyscraper? Because it could; its toes stick to about anything. Engineers can already emulate the secrets of gecko stickiness to make strips of rubbery materials that can pick up and release objects, but simple mass production for everyday use has been out of reach until now.

Researchers at the Georgia Institute of Technology have developed, in a new study, a method of making gecko-inspired adhesive materials that is much more cost-effective than current methods. It could enable mass production and the spread of the versatile gripping strips to manufacturing and homes.

Polymers with “gecko adhesion” surfaces could be used to make extremely versatile grippers to pick up very different objects even on the same assembly line. They could make picture hanging easy by adhering to both the picture and the wall at the same time. Vacuum cleaner robots with gecko adhesion could someday scoot up tall buildings to clean facades.

“With the exception of things like Teflon, it will adhere to anything. This is a clear advantage in manufacturing because we don’t have to prepare the gripper for specific surfaces we want to lift. Gecko-inspired adhesives can lift flat objects like boxes then turn around and lift curved objects like eggs and vegetables,” said Michael Varenberg, the study’s principal investigator and an assistant professor in Georgia Tech’s George W. Woodruff School of Mechanical Engineering.

Current grippers on assembly lines, such as clamps, magnets, and suction cups, can each lift limited ranges of objects. Grippers based on gecko-inspired surfaces, which are dry and contain no glue or goo, could replace many grippers or just fill in capability gaps left by other gripping mechanisms.

Drawing out razors

The adhesion comes from protrusions a few hundred microns in size that often look like sections of short, floppy walls running parallel to each other across the material’s surface. How they work by mimicking geckos’ feet is explained below.

Up to now, molding has produced these mesoscale walls by pouring ingredients onto a template, letting the mixture react and set to a flexible polymer then removing it from the mold. But the method is inconvenient.

“Molding techniques are expensive and time-consuming processes. And there are issues with getting the gecko-like material to release from the template, which can disturb the quality of the attachment surface,” Varenberg said.

The researchers’ new method formed those walls by pouring ingredients onto a smooth surface instead of a mold, letting the polymer partially set then dipping rows of laboratory razor blades into it. The material set a little more around the blades, which were then drawn out, leaving behind micron-scale indentations surrounded by the desired walls.

Varenberg and first author Jae-Kang Kim published details of their new method in the journal ACS Applied Materials & Interfaces on April 6, 2020.

Forget about perfection

Though the new method is easier than molding, developing it took a year of dipping, drawing, and readjusting while surveying finicky details under an electron microscope.

“There are many parameters to control: Viscosity and temperature of the liquid; timing, speed, and distance of withdrawing the blades. We needed enough plasticity of the setting polymer to the blades to stretch the walls up, and not so much rigidity that would lead the walls to rip up,” Varenberg said.

Gecko-inspired surfaces have a fine topography on a micron-scale and sometimes even on a nanoscale, and surfaces made via molding are usually the most precise. But such perfection is unnecessary; the materials made with the new method did the job well and were also markedly robust.

“Many researchers demonstrating gecko adhesion have to do it in a cleanroom in clean gear. Our system just plain works in normal settings. It is robust and simple, and I think it has good potential for use in industry and homes,” said Varenberg, who studies surfaces in nature to mimic their advantageous qualities in human-made materials.

^{[Ready for graduate school with social distancing? Here's how to apply to Georgia Tech.]} 

Gecko foot fluff

Behold the gecko’s foot. It has ridges on its toes, and this has led some in the past to think their feet stick by suction or some kind of clutching by the skin. 

But electron microscopes reveal a deeper structure – spatula-shaped bristly fibrils protrude a few dozen microns long off those ridges. The fibrils make such thorough contact with surfaces down to the nanoscale that weak attractions between atoms on both sides appear to add up enormously to create overall strong adhesion.

In place of fluff, engineers have developed rows of shapes covering materials that produce the effect. A common shape makes a material’s surface look like a field of mushrooms that are a few hundred microns in size; another is rows of short walls like those in this study. 

“The mushroom patterns touch a surface, and they are attached straightaway, but detaching requires applying forces that can be disadvantageous. The wall-shaped projections require minor shear force like a tug or a gentle grab to generate adherence, but that is easy, and letting go of the object is uncomplicated, too,” Varenberg said.

Varenberg’s research team used the drawing method to make walls with U-shaped spaces in between them and walls with V-shaped spaces in between. They worked with polyvinylsiloxane (PVS) and polyurethane (PU). The V-shape made in PVS worked best, but polyurethane is the better material for industry, so Vanenberg’s group will now work toward achieving the V-shape gecko gripping pattern in PU for the best possible combination.

Also read: Lung-heart super sensor on a chip tinier than a ladybug

Here's how to subscribe to our free science and technology email newsletter

Writer & Media Representative: Ben Brumfield (404-272-2780), email: ben.brumfield@comm.gatech.edu

Georgia Institute of Technology

During a stroll, a woman’s breathing becomes a slight bit shallower, and a monitor in her clothing alerts her to get a telemedicine check-up. A new study details how a sensor chip smaller than a ladybug records multiple lung and heart signals along with body movements and could enable such a future socially distanced health monitor.

The core mechanism of the chip developed by researchers at the Georgia Institute of Technology involves two finely manufactured layers of silicon, which overlay each other separated by the space of 270 nanometers – about 0.000001 inches. They carry a minute voltage.

Vibrations from bodily motions and sounds put part of the chip in very slight motion, making the voltage flux, thus creating readable electronic outputs. In human testing, the chip has recorded a variety of signals from the mechanical workings of the lungs and the heart with clarity, signals that often escape meaningful detection by current medical technology.

“Right now, medicine looks to EKGs (electrocardiograms) for information on the heart, but EKGs only measure electrical impulses. The heart is a mechanical system with muscles pumping and valves opening and shutting, and it sends out a signature of sounds and motions, which an EKG does not detect. EKGs also say nothing about lung function,” said Farrokh Ayazi, Ken Byers Professor in Georgia Tech’s School of Electrical and Computer Engineering.

Stethoscope-accelerometer combo

The chip, which acts as an advanced electronic stethoscope and accelerometer in one, is aptly called an accelerometer contact microphone. It detects vibrations that enter the chip from inside the body while keeping out distracting noise from outside the body's core like airborne sounds

“If it rubs on my skin or shirt, it doesn’t hear the friction, but the device is very sensitive to sounds coming at it from inside the body, so it picks up useful vibrations even through clothing,” Ayazi said.

The detection bandwidth is enormous - from broad, sweeping motions to inaudibly high-pitched tones. Thus, the sensor chip records all at once fine details of the heartbeat, waves the heart sends through the body, and respiration rates and lung sounds. It even tracks the wearer’s physical activities such as walking.

The signals are recorded in sync, potentially offering the big picture of a patient’s heart and lung health. For the study, the researchers successfully recorded a “gallop,” a faint third sound after the “lub-dub” of the heartbeat. Gallops are normally elusive clues of heart failure.

The researchers published their results in the journal npj Digital Medicine on February 12, 2020. The research was funded by the Georgia Research Alliance, the Defense Advanced Research Projects Agency (DARPA), the National Science Foundation, and the National Institutes of Health. Study coauthor Divya Gupta, M.D., a cardiologist at Emory University, collaborated in testing the chip on human participants.

Hermetically sealed vacuum

Medical research has tried to make better use of the body’s mechanical signals for decades but recording some – like waves traversing multiple tissues – has proven inconsistent, while others – like gallops – have relied upon clinician skills influenced by human error. The new chip produces high-resolution, quantified data that future research could match to pathologies in order to identify them.

“We are working already to collect significantly more data matched with pathologies. We envision algorithms in the future that may enable a broad array of clinical readings,” Ayazi said.

Though the chip’s main engineering principle is simple, making it work and then manufacturable took Ayazi’s lab ten years, mainly because of the Lilliputian scale of the gap between the silicon layers, i.e. electrodes. If the 2-millimeter by 2-millimeter sensor chip were expanded to the size of a football field, that air gap would be about an inch wide.

“That very thin gap separating the two electrodes cannot have any contact, not even by forces in the air in between the layers, so the whole sensor is hermetically sealed inside a vacuum cavity,” Ayazi said. “This makes for that ultralow signal noise and breadth of bandwidth that are unique.”

Detects through clothing

The researchers used a manufacturing process developed in Ayazi’s lab called the HARPSS+ platform (High Aspect Ratio Poly and Single Crystalline Silicon) for mass production, running off hand-sized sheets that were then cut into the tiny sensor chips. HARPSS+ is the first reported mass manufacturing process that achieves such consistently thin gaps, and it has enabled high-throughput manufacturing of many such advanced MEMS, or microelectromechanical systems.

The experimental device is currently battery-powered and uses a second chip called a signal-conditioning circuit to translate the sensor chip’s signals into patterned read-outs.

Three sensors or more could be inserted into a chest band that would triangulate health signals to locate their sources. Someday a device may pinpoint an emerging heart valve flaw by turbulence it produces in the bloodstream or identify a cancerous lesion by faint crackling sounds in a lung.

Here's how to subscribe to our free science and technology newsletter

Also read: Digital tool helps with tough COVID19 decision

These researchers co-authored the study: Pranav Gupta (first author), Mohammad Moghimi, Yaesuk Jeong and Omer Inan from Georgia Tech. The research was funded by the Georgia Research Alliance, the Defense Advanced Research Projects Agency (DARPA) Technology Office’s Advanced Inertial Micro Sensors program (contract # N66001-16-1-4064), and by the National Science Foundation/National Institutes of Health Smart and Connected Health Program (grant # R01 EB023808). The team’s work with human subjects was approved by Emory University and Georgia Institute of Technology Institutional Review Boards (IRB# H18248). Any findings, conclusions or recommendations are those of the authors and not necessarily of the sponsors.

Writer & Media Representative: Ben Brumfield (404-272-2780), email: ben.brumfield@comm.gatech.edu

Georgia Institute of Technology

Georgia Tech Arts is still seeking projects for the 2021 ACCelerate: ACC Smithsonian
Creativity and Innovation Festival in Washington, DC. All Georgia Tech students, faculty, and staff are invited to apply by May 1, 2020.

Even if you do not have a finished project exploring the intersection of science,
engineering, art, design, and technology, we encourage you to speak with Es
Famojure at esther.famojure@arts.gatech.edu about your concepts.

Learn about Georgia Tech's 2019 participants for some inspiration.

The festival brings together all institutions included in the Atlantic Coast Conference to
celebrate creativity and innovation with a specific focus on science, engineering, arts, and
design. It will be held April 9 -11, 2021 at the Smithsonian National Museum of American
History.

Submit your project for consideration by May 1, 2020 to be considered.

LEARN MORE & APPLY

News Contact

COVID-19 has caught Pinar Keskinocak well prepared. For years, she has studied how societies manage pandemics, and how outbreaks overtax the health care system and wrack supply chains to worsen pandemics. Here she shares her insights.

Empty classrooms and supermarket shelves marked the beginning of the COVID-19 pandemic. But Keskinocak expects more signs of the times to come – such as pop-up pandemic clinics and the shortage and rationing of medical supplies beyond masks and ventilators.

Keskinocak is the director of the Center for Health and Humanitarian Systems at the Georgia Institute of Technology, which studies how government and private sectors can cooperate to handle health and humanitarian crises. And she is William W. George Chair and Professor in Georgia Tech’s H. Milton Stewart School of Industrial and Systems Engineering.

In previous research, Keskinocak’s team created a model that accurately ran the course of the 1918 Spanish flu pandemic, and when COVID-19 struck, her team was already in the middle of modeling how special clinics could significantly slow a pandemic. In the meantime, temporary clinics in Wuhan, China, appear to have validated her model.

Healthcare expansion now

The surge of COVID-19 patients pushed Italy’s health care system into a very ugly crisis, and the U.S. needs to take measures now to handle similar patient surges. Pandemics often strike in two waves or more, and the second is usually the worst, so measures need to be lasting, Keskinocak said.

Even without COVID-19, the U.S. healthcare system has been under strain. Emergency rooms are often overcrowded; it takes a long time to schedule an appointment, and there is a chronic shortage of nursing staff.

[Read Keskinocak's guest op-ed in the New York Daily News: COVID clinics now]

“We need to expand capacity and unleash creative flexibility in our healthcare systems. We should use more telemedicine and create self-service stations for testing. I would particularly like to see specialized COVID-19 clinics established now,” Keskinocak said.

“Special clinics could be separate spaces in existing facilities or standalone facilities. As COVID-19 spreads, we expect a lot more people with cold- and flu-like symptoms to seek testing and care. The healthcare capacities are just not there for a business as usual approach, and taking it could harm patients by delaying care and increasing risk of infection.”

Gathering COVID-19 patients in tight spaces like waiting rooms with other patients would increase the coronavirus’ spread, and patients with preexisting conditions could face mortal threat. Contagion could also spread into hospitals.

“Dedicated pandemic clinics could implement targeted hygiene, air filtration, and specialized protective equipment beyond masks and gloves for healthcare workers. They can tailor workflows to test and care for patients quickly and effectively and keep them away from other patients and staff,” Keskinocak said.

Payment needs to be easy, too, including financing the uninsured. In the middle of a public health emergency, it is vital to not get bogged down by restrictions meant for normal times.

Potentially dangerous shortages

Toilet paper will make a comeback in supermarkets, but in its place, life-saving medications could become perilously scarce. Countries need to act now to prevent this from compounding the COVID-19 crisis.

“Dwindling availability of hospital beds, ventilators, and personal protective equipment like masks and gloves during a patient surge – those are the obvious things. But we could also see shortages of items like asthma medication or antidepressants. Worst case, even food supplies could run low,” Keskinocak said.

[Read Keskinocak's guest op-ed in The Hill: medical supply chain dangers]

Here’s how shortages work and can lead to price gouging and also rationing. The latter can have good effects.

“Shortages are the result of supply-demand imbalance caused by either an unexpected increase in demand or unexpected decrease in supply or both. Shortages are common in crises such as natural disasters or health emergencies. But given the worldwide slowdown of economic activity in pandemics, disruptions could get much worse this time,” Keskinocak said.

“Supply chains are actually intricate webs of multiple parts that span the globe. Pandemics damage many of those parts, and it can take time to recover. This creates a more serious and worrisome imbalance between supply and demand.”

Toilet paper will return because people fear-hoard it in a panic but consume it at normal rates. When the panic runs its course, demand slows back down to the actual rate of consumption and its normal supply chain, which is relatively simple, catches up.

“With medicine and healthcare services and supplies, the increase in demand is typically already in line with consumption, so a shortage in supply or increase in demand can create a supply-demand gap that continues for a long time,” Keskinocak said. “Medical supply chains are also very complex and fragile.”

Future vaccine distribution

In normal times, most supply chains work at a plodding pace, and when crisis strikes, it is tough to ramp them up due to expensive equipment, complex logistics, and strict regulations, particularly in health care. Even temporary shortages of medicines and medical devices can have consequences for patients who need them.

“If shortages become serious, rationing – with a priority allocation to those most in need – can help balance demand and supply for critical items like medications.”

Once created and approved, the production of vaccines or antivirals for COVID-19 will ramp up slowly and could be in short supply at first. Decision-makers need plan investments now in the supply chains necessary for their effective distribution.

This will include painful, necessary decisions like prioritizing first doses for healthcare workers, people with pre-existing conditions, and the elderly. The current system of restocking vaccines in the U.S. after initial distribution also has serious gaps that need fixing to save many more lives.

In the meantime, social distancing is one of the best ways to protect everyone and reduce the patient surge into clinics. Do it if you or anyone in your household has any cold-like symptoms.

[Read Keskinocak's commentary on social distancing on AJC.com]

Also read: Vaccine Supply Gaps Can Make Pandemics Deadlier

Media contacts: Ben Brumfield (ben.brumfield@comm.gatech.edu) and John Toon (john.toon@comm.gatech.edu)

News Contact

WHEN: June 7-9, 2017

WHERE: UN City, Copenhagen

WHAT: Panels and interactive sessions focusing on topics such as:

• Global Health Emergencies
• Innovation and Influencing Markets
• Strengthening Health Supply Chains

TO REGISTER ONLINE please visit chhs.gatech.edu/conference/2017/registration. 

*As the 2017 conference will be hosted at the United Nations City, it will be free of charge. All attendees must be registered online prior to the event and must present an official form of government-issued photo ID to enter the UN City conference venue.

OVERVIEW:

The HHL Conference is pleased to announce the opening Keynote address from Dr. Richard Brennan, Director of Emergency Operations, Emergencies Programme, World Health Organization (WHO) in geneva, who led the Ebola Response from October 2014 to January 2016 as the Director at the WHO HQ. Dr. Brennan now oversees WHO’s response to health emergencies globally as part of the new Emergencies Programme which brings together several departments to streamline WHO’s role in emergencies globally, from prevention and preparedness to response, and from humanitarian emergencies to disease outbreaks. See full bio here.

Each year the Conference on Health & Humanitarian Logistics (HHL) provides an open forum for the discussion of challenges and new solutions in disaster preparedness and response, long-term development and humanitarian aid, and global health delivery. This neutral platform encourages learning and collaboration within and across institutions; promotes system-wide improvements in organizations and the sector as a whole; identifies important research issues; and establishes priorities in terms of strategies, policies and investments.

Speakers and participants in the event come from across global health and humanitarian sectors, from governments, NGOs, foundations, private industry, and academia, and share diverse perspectives in health and humanitarian challenges. The agenda features keynote addresses, panel discussions, focused interactive workshops, oral presentations, lunchtime group discussions, and interactive poster sessions covering a broad set of research topics and applications.

Submissions were accepted for 3 categories this year: interactive workshops, oral presentations, and posters, which explore challenges and solutions for building efficient and effective supply chains for health and humanitarian challenges. Particular topics of interest include public private partnerships, innovative uses of data or technology, and creating sustainable supply chain systems.More information about these sessions is available here. The final list of presentation, workshop sessions, and posters will be online at the links here as they are confirmed.

2017 Conference Co-organizers:

• Özlem Ergun, Northeastern University
• Jarrod Goentzel, Humanitarian Response Lab, MIT
• Etleva Kadilli, UNICEF Supply Division, Copenhagen
• Pinar Keskinocak, CHHS, Georgia Tech
• Julie Swann, CHHS, Georgia Tech
• Luk Van Wassenhove, Humanitarian Research Group, INSEAD

2017 Speakers and presenters include representatives from:

Bill & Melinda Gates Foundation, Centers for Disease Control & Prevention, (CDC), Central Medical Stores Trust of Malawi, Chemonics International, DHL, Earthquake Reconstruction & Rehabilitation Authority (ERRA) Pakistan, GS1 Nigeria, Global Scientific Solutions for health, Imperial Health Sciences, John Snow Inc., Laerdal Global Health, Logistimo India, Medecins Sans Frontieres, National Medical Stores Uganda, National Primary Health Care Development Agency of Nigeria, Nexleaf Analytics, North Star Alliance, Partnership for Supply Chain Management, UCLA, Vienna University of Economics and Business,  UNICEF Supply Division, UN World Food Programme, UPS, World Health Organization, USAID, and more.

News Contact