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12 June 2017

Very wearable wearables usher in new paradigm in healthcare

Wearables including temporary tattoos are contributing
to a paradigm shift in healthcare monitoring;
above, a slide from a presentation by Nanshu Lu
on graphene electronic tattoos for monitoring organ function.

Wearable devices, materials, and even temporary tattoos are entering healthcare and other markets, offering the potential for faster, more accurate, and potentially life-saving treatment.

Tracking and measuring activity in the 11 major organ systems in the human body systems is imperative for medical providers to quickly and accurately diagnose and treat patients experience trauma or other emergencies. But existing medical equipment may be uncomfortably bulky or take valuable time to set up.

Skin-like devices and other technologies can provide unobtrusive, comfortable, and precise alternatives for sensing what is happening inside the body.

In one development, researchers at the University of Texas at Austin are developing a skin-like temporary tattoo that takes measurements of electrical signals from the heart, muscles, and brain (see a video presentation in the SPIE Digital Library and a report in IEEE Spectrum).

Nanshu Lu and Deji Akinwande of the University of Texas at Austin have developed a method for making graphene electrodes that may be applied to the skin, much like a temporary tattoo.

Lu and Akinwande invented epidermal electronics with John Rogers of the University of Illinois at Urbana-Champaign six years, Lu told an audience at SPIE Smart Structures and Materials and Nondestructive Evaluation in Portland, Oregon, in March.

Their process starts “by growing single-layer graphene on a sheet of copper,” Lu explained in IEEE Spectrum. The 2D carbon sheet is coated with a stretchy support polymer, and the copper is etched off.

Next, the polymer-graphene sheet is placed on temporary tattoo paper, the graphene is carved to make electrodes with stretchy spiral-shaped connections between them, and the excess graphene is removed.

The sensor is then applied by placing it on the skin and wetting the back of the paper.

“The next step is to add an antenna to the design so that signals can be beamed off the device to a phone or computer,” Akinwande said.

Lu and Akinwande will give updates on their work in featured talks at SPIE Optics and Photonics in San Diego in August.

Among other advances being reported at the meeting in San Diego by groups working in wearables for healthcare:

  • Matti Mantysalo, Tampere University of Technology, et al. will present on printed soft-electronics for remote body monitoring, including fabrication and characterization of electrode bandages and temperature sensors (10366-13). Among wearable electronics entering consumer markets over the past few years, wrist devices and textile integration are common technologies for unobtrusive measuring during sport and for well-being, they say, and disposable bandages represent a paradigm shift.

  • Raphael Pfattner and others in the research group of Zhenan Bao of Stanford University have been working with material properties for stretchable electronics for wearable devices, to overcome severe limitations that may be posed by organic materials (10365-9).

  • Benjamin Tee of the Institute of Materials Research and Engineering in Singapore will cover a variety of dramatic changes in how we interact with the digital environment, in his paper on optogenetic electronic skins (10366-16) — for example, robots can don sensor active skins to shake human hands with comfortable pressure, measure health biometrics, and possibly aid in wound healing.

  • Piero Cosseddu, Universit√† degli Studi di Cagliari, et al. will show how organic charge-modulated field-effect transistors can be routinely fabricated on highly flexible, ultraconformable thin films and used for monitoring pH variations with a very high degree of sensitivity (10364-19). Their approach has been applied for monitoring cell metabolic activity as well as electrical activity of excitable cells.

Healing wounds, monitoring organ function, “seeing” inside the body — just a few of the ways that wearables are changing our lives.

08 June 2017

What does space technology have to do with medicine?

Ultraviolet image from NASA’s Galaxy Evolution Explorer
shows NGC 3242, a planetary nebula frequently referred to
as “Jupiter’s Ghost.” Image courtesy NASA/JPL-Caltech
Are there any connections between space technologies and healthcare?

You bet there is, says Shouleh Nikzad, senior research scientist at NASA’s Jet Propulsion Laboratory (JPL) at the California Institute of Technology (Caltech) and the principal engineer, co-lead, and technical director for JPL’s Medical Engineering Forum.

Numerous optics and photonics technologies originally developed for space applications have found their way into consumer and medical markets, Nikzad writes in the April 2017 issue of SPIE Professional magazine.

Infrared thermometers, workout machines, compact cameras in mobile phones, and imaging technologies are just a few familiar examples.

Ultraviolet imaging is also used in medical applications
to reveal disease, as in this image of cancerous brain tissue.
Although applying astrophysics technologies to medical applications may appear difficult, there's a certain synergy between these two fields.

"As explorers, we invest great efforts and resources to develop sensors and instruments to measure signatures from faint objects, characterize planetary atmospheres, observe the remnants of dying stars, explore planetary bodies, and search for signs of life," she says.

"These applications require high sensitivity and high accuracy from reliable, robust, compact, low-power, low-mass, noninvasive instruments that can work in harsh and unfriendly environments.

"This probably sounds familiar to those in medical sciences and medical practice," she says. "As human beings, we invest great efforts and resources to help patients. We try to detect faint signals that differentiate good cells from bad, get close to the area of interest without disturbing other areas, … and look for signs of life.

"These conditions also require high sensitivity and high accuracy from reliable, robust, compact, low-power, low-mass, noninvasive instruments that can work in unfriendly environments."

Take the example of the Electronic Nose for environmental monitoring of crewed space missions. JPL developed the ENose to fly on the NASA Space Shuttle during John Glenn Jr.’s second historic flight in 1998 as well as on the International Space Station.

Modeled after the way a mammal’s nose operates, the ENose can be trained to recognize patterns and therefore detect the presence and levels of substances that might be harmful to astronauts.

Some time later, scientists at JPL and the City of Hope, inspired by the fact that some dogs can sniff cancer, collaborated to use the ENose in a proof-of-concept experiment to determine whether the technology can distinguish normal cells from brain-cancer cells and skin-cancer cells.

Ultraviolet imaging is also used in medical applications to reveal disease, as in this image of cancerous brain tissue.

And the benefits between space technologies and medical applications go both ways.

A team from JPL and the Skull Base Institute, for instance, originally developed MARVEL, a multiangle, rear-viewing endoscopic tool, for minimally invasive brain tumor removal. As described in "4-mm-diameter three-dimensional imaging endoscope with steerable camera for minimally invasive surgery (3-D-MARVEL)," in the journal Neurophotonics, the tool has stereoscopic vision and fits within a small 4-mm-diameter tube.

It was not long before a space application for the technology was realized. The MARVEL innovation can be used to remotely sense and verify the rock and soil samples collected by robots from planetary bodies, before the samples are returned to Earth.

Photonics technologies not only make for a better world, they are literally out of this world!

20 March 2017

Ants, bees, and octopuses: bioinspired robotics, drones, and smart structures

Ready to fly
Robotic pollinator
Photo and video: Miyako et al.
Can you imagine a world in which our crops and flowers are pollinated by autonomous drones the size of bees? Researchers at Japan's National Institute of Advanced Industrial Science and Technology believe this reality could be closer than we may think due to staggering declines in bee populations around the world.

Eijiro Miyako and his colleagues have used the principle of cross-pollination to engineer a bioinspired robotic pollinator, which can mimic the functionality of real bees, reports an article published in Science Direct. Measuring 4 centimeters wide and weighing a mere 15 grams, each drone is equipped with a strip of horsehair coated in an iconic liquid gel, allowing it to pick up pollen from one flower and deposit it in another.

"GPS, high-resolution cameras and artificial intelligence will be required for the drones to independently track their way between flowers and land on them correctly, " said Miyako.


While other methods sometimes prove to be more practical in some applications, bioinspired technology offers unique solutions to a wide variety of complex problems across numerous industries, and research is advancing.

Bioinspiration, Biomimetics, and Bioreplication VII, a conference focused on research and technology influenced by natural biological processes found in a variety of plants and organisms, will feature reports on research for several applications areas.

The conference is one of 11 being presesnted at SPIE Smart Structures/Nondestructive Evaluation 25–29 March in Portland, Oregon.

Among the presentations, David Hanson of Hanson Robotics, Ltd., will report in an all-conference plenary talk on research investigating how conventional motors limit bioinspired robotics and how electroactive polymer (EAP) actuators and sensors improve simplicity, compliance, and physical scaling in motors driving robotics. Hanson will also describe bioinspired advantages in robotic locomotion, grasping, manipulation, and social expressions, and present a roadmap for EAP actuators in bioinspired intelligent robotics.

In "Foldable drones: from biology to technology," Dario Floreano, Stefano Mintchev, and Jun Shintake of the Swiss Federal Institute of Technology in Lausanne will discuss the advantages and current limitations of adaptive morphological capabilities in drones.

Foldable wings enable better transition between aerial and ground locomotion, advancing the development of multimodal drones for extended mission envelopes. Currently, the potential of foldable drones is limited by the use of conventional design strategies and rigid materials. Tackling this challenge includes the development of structures that can become soft during morphing and stiff during regular operation by using origami structures or variable stiffness materials such as EAPs.

Folding, crawling, gripping -- to save lives

In other work drawing inspiration from nature, Michael Tolley of the University of California, San Diego, reported last August at SPIE Optics + Photonics on his team’s work in creating small robots capable of folding, gripping, or crawling through small spaces.

The goal is to create smart robots capable of working in uncontrolled environments, such as search and rescue missions or inhospitable locations, Tolley said.

One inspiration came from a particular seed pod in a very dry area of the world. The pod unfolds when the humidity is just right, releasing seeds.

In another capability, an ant-inspired gripper starts as a 2-D piece of layered plastic and folds into a useful little robot capable of moving objects. Rather than fold the robots by hand, Tolley’s research team developed layered structures that self-fold into pre-printed shapes when heat is applied. Adding localized heating to the structure allows for sequential folding; heating the structure in one area, then the next area leads to self-folding structures – even furniture.

Typical robots are made of material too hard and tough to be flexible. However, using silicone elastomers, Tolley created a soft-bodied robot – inspired by soft-bodied octopuses that are capable of squishing through very small spaces – that could tolerate heat, water, and getting run over, all while being flexible and capable of crawling along using inflatable pneumatic tubes. This soft-bodied robot may come to rescue earthquake victims one day.

Tolley's group will present on "Fluid electrodes for submersible robotics based on dielectric elastomer actuators," at SPIE Smart Structures/NDE in the conference on EAP Actuators and Devices.

Guest blogger Elizabeth Bernhardt, research assistant in nonlinear optics at Washington State University, reported on Michael Tolley's research from 2016 SPIE Optics + Photonics. 

08 March 2017

Celebrating women in optics and photonics: stories to inspire

International Women's Day has been observed on 8 March for more than 100 years, and Women's History Month is celebrated variously in March (Australia, the United Kingdom, and the United States) and October (Canada) for nearly as long. (See some of that history via The Huffington Post.)

Women in optics are celebrated year-round in a planner produced by SPIE, the international society for optics and photonics. The 2017 version features comments from 28 women in multidisciplinary fields within science, technology, engineering, and mathematics (STEM), sharing their inspirational stories, crediting influential mentors and role models, and lending valuable advice to others considering careers in STEM. (The planner is distributed at no charge; to get yours, email CustomerService at SPIE.org.)

The SPIE 2017 Women in Optics Planner includes comments
from women such as Irene Sterian, ReMAP, who advises,
"If you are interested in STEM, have passion and dream big.
Take calculated risks, meet challenges with creativity, and
turn failures into assets. Failure is the colleague of
success; it takes both to balance the equation.
Industries and disciplines falling under the umbrella of STEM have often proven to be challenging environments for women. In addition to celebrating women's accomplishments in the annual planner, SPIE Women in Optics programs serve in a number of ways to explore how the professional environment and culture within the optics and photonics community can better facilitate equal employment opportunities, rewards, and recognition for members, irrespective of their gender. Efforts focus on identifying measurable steps to improve ongoing advocacy and career support for women, as well as attract more women to careers in optics and photonics.

To better understand gender disparity issues within the optics and photonics community, a series of questions have been incorporated into the annual SPIE Global Optics and Photonics Salary Survey, helping to set the stage for real and measurable change in the community. The 2016 report produced many key findings; some expected and some that may come as a surprise.

Women made up 17% — about the same as their representation in SPIE membership and at SPIE events — of the 7,000 survey respondents from 105 countries.

Among the findings related to gender:
  • Median salaries are 38% higher overall for men than for women. The salary gap is smallest during early career and grows over time.
  • Wage gaps persist in most demographic subsets of the data, though gaps are lowest in early career stages, non-existent in lower-income Asian countries, and reversed in lower-income Europe.
  • Women’s representation in the workplace declines over time. At the earliest career stage, 26% of workers are women, but participation drops with increasing years on the job, reaching 11% for employees with thirty or more years at work.
  • Men and women are similarly satisfied about most aspects of their careers — more than 90% of both genders enjoy their work and find it meaningful. In contrast, fewer women feel that they are paid fairly (69% women versus 76% men), and that promotions are handled fairly at their organizations (59% women versus 65% of men).

First task: combat unconscious bias

First, combat unconscious bias, advised Kuheli Dutt
In a compelling presentation at SPIE Photonics West in San Francisco, California, a few weeks ago, Kuheli Dutt, Assistant Director for Academic Affairs and Diversity at Columbia University’s Lamont-Doherty Earth Observatory (LDEO), offered counsel based on extensive studies.

“One cannot address a problem if a majority of people don’t believe there is one,” Dutt pointed out.

Presenting only a fraction of the research on gender bias in the STEM workplace, Dutt addressed how the natural tendency to develop subconscious biases has led to vast under-representation of women and minorities, and created an environment that favors men.

She outlined recommendations for organizations wanting to create a culture of inclusion:
  • examining search committee procedures
  • adjusting work-life-balance and family-friendly policies
  • embracing institutional accountability and transparency and mentoring programs
  • advocating for visibility and recognition of women and minorities.

Most importantly, she urged individuals and organizations both to acknowledge that awareness of implicit bias was key to the successful implementation of change.

Dutt also tasked women and minorities in STEM to find their voices to influence awareness. As scientists, she said, "go back to the data," and advocate for yourself and for other women in science.

Reporting from SPIE Photonics West by Alison Walker, SPIE, the international society for optics and photonics.

07 March 2017

Temperature-sensitive technology for artificial skins: smart structures

Researchers around the world are in the midst of developing artificial skins essential to modern robotics, prosthetic limbs, and other applications. Designed to emulate the most practical properties of human skin, some artificial skin technologies have managed to surpass the sensory capabilities of living tissues. One such technology is a temperature-sensitive electronic film, which has paralleled the record performance of the world's most sensitive heat-detecting organism, the Crotalinae, commonly know as the pit viper.


While in the process of fabricating materials for synthetic wood, a team of researchers discovered a film made of pectin, a sugar molecule responsible for the temperature sensitivity in plants, could exhibit an electrical response to changes in temperature when enriched with positively-charged calcium ions. This finding led to the study "Biomimetic temperature-sensing layer for artificial skins" by senior author Chiara Daraio, et al., which was published in the February issue of Science Robotics. The transparent and flexible pectin films under examination were incorporated into artificial skins made from elastic materials such as silicon rubber, then tested for sensitivity.

Pectin is considered a bionic material; a class of materials utilized to preserve, enhance, and exploit properties of living systems for engineering purposes. Until now, bio-engineering synthetic materials that reproduce or surpass the performance of natural materials has been intangible. Fabricating the synthetic pectin material by combining carbon nano-particles in a matrix of plant cells, has resulted in new temperature sensors with record-breaking responsivity.

Flexible pectin film
Photo: Caltech/Science Robotics

When temperatures rise, molecules of pectin detach from one another, releasing calcium ions that can be detected by electrodes embedded in the film. Artificial skins containing the pectin film can precisely map temperature variations across its surface. From the gentle touch of a finger to warm objects–a teddy bear microwaved to 37° C–a meter away, the films maintain their sensitivity even after being warmed and cooled over 215 times, as well as experiencing physical deformations, a highly desirable trait for artificial skins.


The pectin films “are extremely easy to fabricate and extremely low cost—you can buy pectin at your local supermarket to make gelatin, jams, or jellies,” said Daraio, Professor of mechanical engineering and applied physics and materials scientist at the California Institute of Technology. “We think it’s pretty straightforward to scale up to large-scale production if needed."

Daraio will share her team's research in a plenary presentation titled "Plant nanobionic materials for thermally active, soft, artificial skins" at SPIE Smart Structures/NDE in Portland, Oregon. Spanning 25–29 March, the symposium offers a unique collaboration between engineers who develop advanced materials and researchers who use sensor networks and non-destructive evaluation methods to monitor the health of structural and biological systems.