By Maegan Murray, ���سԹ�

RICHLAND, Wash. – Engineering researchers at Washington State University Tri-Cities, in partnership with those at the in Germany, have developed a way to 3D print flexible sensors using nanomaterials and a type of plastic in tandem, which has shown to advance capabilities for what is possible with flexible sensors.

Flexible sensors have applications in soft robotics, prosthetics, physical therapy and structural health monitoring, which requires a degree of movement, compression or flex to fulfill the function of a device and/or the use. The sensors may be used to measure the degree of stretching or compression in the movement of an object, the amount of times something is used, flexed or compressed, or to track how something moves.

Until now, manufacturers have found it challenging to create a sensor that would integrate seamlessly with material within a larger system. Using their 3D printing method to create the sensors, however, several materials are printed in tandem. This would allow manufacturers to better create complex and conductive pattern designs, in addition to specifically tailor the general manipulation needed with each type of sensor. This method uses extrusion to make feedstock material and thus following a 3D printing method would also allow the sensors to be mass-produced on a commercial scale.

The team of WSU and Leibniz Institute researchers, made up of Josef Christ, Nahal Aliheidari, Petra Pötschke and Amir Ameli, recently published their findings in Polymers, an MDPI research journal.

Varied potential and recyclable

Ameli, ���سԹ� assistant professor of mechanical engineering, said they started with nanomaterials called carbon nanotubes and a flexible polymer called

thermoplastic polyurethane, which can be combined in different amounts and in different ways depending on the type of use.

“We can design sensors with different sensitivity and different range of flexibility,” he said. “We can go as high as 100 percent deformation, which has wide use for applications including soft robotics. It is conformable, it is soft, it is flexible, and at the same time, it has a good sensitivity to sense the change in dimensions.”

Ameli said using 3D printing, they have designed bi-directional sensors, which allow the sense of deformation in two different directions.

“By monitoring the change in the electrical resistance, we can probe how much deformation is applied to the sensors, which is called piezoresistivity,” he said. “We can print these with conductive traces of nanomaterial with different patterns and in different directions. That gives us the ability to design sensors with tuned sensitivity and in any direction we are interested in.”

Ameli said the material is also recyclable.

“We can melt it and then re-melt it, and through the melting process, we can recycle the material,” he said.

Applications in robotics, physical therapy

So far, they have done initial tests with the sensors in a glove prototype, with a robot that is being developed at WSU to pick apples, as well as with a few other applications. They also have plans for printing nanomaterials that can be used in supercapacitors, or those that can hold and store large amounts of energy, in addition to a number of other areas.

With the glove prototype, they used the sensors in the fingers of the glove, measuring how much the sensor contracted and expanded with the movement of the fingers. The sensors could also be used to sense the strain in the movement, which could simulate the strain that a person’s hand endures with a particular movement. It could also monitor the amount of times a person moves particular parts of their hands for studies in physical therapy and ways to improve movement.

In the robot being developed for picking apples, the sensor would be applied on the device that would grip the apples to trace the amount of pressure needed in order to not bruise apples.

“For example, if we want a robotic hand to touch and grab sensitive objects, like in apple-picking, the apple is sensitive and we don’t want to use a hard gripper to grip it because it will bruise the apple,” Ameli said. “We can sense where the touch is made and send the feedback to the computer controlling the device.”

For more information on the technology, contact Ameli at 509-372-7442 or a.ameli@wsu.edu.

By Maegan Murray, ���سԹ�

RICHLAND, Wash. – Two teams at Washington State University Tri-Cities have partnered with Washington River Protection Solutions to procure and program an autonomous vehicle and develop a form of ultra high-performance concrete to help protect workers in radioactive areas at the Hanford Site and safely immobilize solid secondary wastes.

WRPS is the U.S. Department of Energy’s Tank Operations contractor responsible for managing Hanford’s 56 million gallons of highly radioactive waste and preparing it for delivery to the Waste Treatment Plant on the site. The partnership for the projects will provide WRPS with customized technology to fit their needs, in addition to further improving the safety capabilities of its employees and environmental impact stemming from the tank farms at the Hanford Site.

Robotics to analyze radioactive vapors

WRPS provided a WSU team with an initial contract to procure and program an autonomous vehicle that would be used for measuring vapors, or chemical gases, within the tank farms.

The WSU team consists of Akram Hossain, vice chancellor for research, graduate studies and external programs; Scott Hudson, professor of electrical engineering; John Miller, associate professor of computer science; and Changki Mo, associate professor of mechanical engineering.

The team plans to purchase a pre-fabricated, compact and programmable vehicle, which has the capacity to hold 40-50 pounds of equipment. The team will then eventually outfit, customize and program the vehicle for its desired purpose within the tank farms. The vehicle must be able to follow a defined path, dock itself to charge its battery, withstand long-term use, be able to run autonomously, as well as allow manual override operations.

“This vehicle will be going into areas, minimizing personnel entries, so we need to assure that it can operate reliably and it won’t break down,” Miller said “We have to make certain that the quality is of impeccable standards and that the system can demonstrate operational longevity in these areas.”

The design of the autonomous vehicle marks the first phase of what will potentially turn into a multi-phase project. WRPS has also expressed interest in having the robot detect obstacles in a changing environment, change filters at the site and monitor radiation. Miller said those challenges will most-likely be addressed in future phases of the project.

“This is a great opportunity, both for WSU, as well as for our students,” Miller said. “It creates opportunities for undergraduate research, as well as providing funding for graduate research. It is the perfect opportunity for us.”

The team plans to have the first phase of the autonomous vehicle completed and demonstrated to WRPS in the next few months. The team will conduct demonstrations and additional phases of development over the course of the year. When fully developed, the autonomous vehicle would be deployed in tank farms to support construction and operations.

Ultra high-performance concrete to encapsulate nuclear waste

Srinivas Allena, ���سԹ� associate professor of civil and environmental engineering, received a contract to develop an ultra-high performance cementitious

material to potentially be used as a grout to encapsulate solid secondary waste from the Hanford tank farms.

“WRPS is currently using a grout that they obtain from a local concrete supplier, which uses a regular cement mix with sand and some other chemical additives,” Allena said. “But the goal with our research is to use locally available materials to create a composite with low permeability, superior durability and greater stability that would perform at the same level as the commercially available pre-packaged ultra high-performance concrete.”

Allena said there is currently limited types of ultra high-performance concrete available on the market with high operational costs associated with use of the material. He said by using locally available materials and by optimizing mixture constituents with those that are more environmentally friendly with his team’s composite, however, they would be able to keep the costs low, while maintaining the same quality in the concrete and reducing the impact to the environment.

“We will be able to compare our grout materials with properties that WRPS is currently using and show the improved properties,” he said. “The goal is to provide a cheaper, more environmentally friendly option that will compete with the best product on the market.”

The team plans to have initial mixtures ready with their mechanical and durability properties evaluated by September.

The projects are a part of solving some of the world’s . They pertain particularly to developing and by harnessing technology to improve quality of life. The projects are also in line with WSU’s

By Adrian Aumen, WSU College of Arts & Sciences

In a cold, dimly blue-lit room, a strange human–animal hybrid paces before the entrance to a fiery red cave. When the “Huminal” senses a viewer approaching, it stops, turns its head to stare at the visitor and emits its own red-hot glow. The viewer must then decide how to respond to the apparent challenge: continue toward the creature or retreat.

The Huminal is an interactive, kinetic sculptural installation featuring an autonomous, mobile robot that senses and responds to changes in its environment. Created by an interdisciplinary team at Washington State University Tri-Cities, it incorporates research and techniques in fine arts, design, electrical and mechanical engineering and robotics to provide a unique platform for exploring the relationship between humans and machines—and, it turns out, between artists and engineers, too.

Two years in the making and nearing completion this month, The Huminal is the third and most complex art-machine designed and built in as many years by fine arts professor Sena Clara Creston in collaboration with WSU engineering students and faculty. It debuted recently to rave reviews at a robotics exposition for employees of Pacific Northwest National Laboratory in Richland, where Gordan Gavric, a key member of the Huminal development team, is an electrical engineering intern.

“The feedback we’ve gotten so far is really great,” said Gavric, a senior in engineering and president of the ���سԹ� Robotics Club. “People recognize it’s a robot, but at the same time they’re a little creeped out. How do people want to interact with a creepy robot?”

Designed to pique curiosity along with uneasiness, the Huminal is about the size and shape of a large dog and covered with white plastic discs resembling scales or fur. Its four jointed legs give the appearance of walking as it rolls in an elliptical path outside its apparent den.

Multiple internal sensors, a camera and a small Raspberry Pi computer communicate with microcontrollers across two electronic systems to direct the robot’s movements and trigger the pulsing red LED lights in its chest. The steady hum of its heart—two 8.6 volt motors—is interrupted only when a sensor detects nearby movement. At that point, the Huminal is programmed to stop in its tracks, turn its head to face the approaching object and transmit its warning glow.

“I look forward to seeing how more people react to it,” Gavric said. “Is it alive? Is it human? The mystery is unnerving and it’s this uneasiness that Sena is trying to exploit.”

A corporeal experience

����, Creston builds interactive art-machines to create a corporeal experience for viewers. Her artworks invite people to engage with machines and familiar materials in unfamiliar settings and ways. Environmental impact and social consciousness are frequent themes.

“Some people get really aggressive with the work and some are really careful with it,” she said.

By enabling viewers to choose their response to her art, she hopes to help them understand other ways they affect the wider world.

From the haunting  to the satirical —an immersive environment of post-consumer electronics—to the dreamlike —a land-roving, steampunk-style sailboat—much of Creston’s art employs fantasy while exploring intersections between the natural and the man-made.

“Part of it is movement, part of it is response, part of it is material and part of it is social engagement,” she said.

She will talk about her innovative artwork at 1:00 p.m. Saturday, Sept. 16, as part of  events at Uptown Theatre in Richland, Washington.

To create the Huminal’s skin, Creston cut up dozens of discarded plastic water bottles—familiar and somewhat controversial objects that connect the organic and inorganic.

“Many people across the world live with an unsafe water supply, yet we think of water as the source of life and the source of health and wellbeing, and water bottles deliver that,” Creston said. “However, the water bottle itself is not biological or biodegradable—it’s inorganic and it’s not going away. So the material itself becomes this questionable component.

“How do we actually feel for the inorganic and how do these things elicit responses?”

Collaborating in uncommon opportunities

Giving form to Creston’s layered ideas and complex inventions often requires more technical skills than she possesses. So for the past 10 years, she has been learning and implementing modest means of physical computing and mechanical engineering.

“But, as my mentor explained, I didn’t need to learn how to do everything—I needed to learn how to collaborate,” she said.

Fortunately, interdisciplinary collaborations are strongly encouraged and available at WSU. Engineering professors Changki Mo at ���سԹ� and Charles Pezeshki and Jacob Leachman at WSU Pullman recognized the uncommon opportunities Creston’s projects offered their students and wove them into their coursework.

“Her projects presented the perfect combination of an interesting customer, an achievable design and the monetary scope to take some risks in a shared learning experience,” Pezeshki said.

Students in Pezeshki and Leachman’s junior-level design classes worked remotely with Creston to create The Umbrellaship and Machinescape. The installations were designed, like The Huminal, to question the relationship between humans and their perceived environment.

Eric Loeffler, a May graduate in engineering who constructed the Huminal’s aluminum frame, said he and other students on the project gained a variety of valuable hands-on experiences not usually available to undergraduates.

For example, Loeffler learned new design software applications that he can use in his master’s degree program, and he expanded his welding skills to include aluminum materials.

“There were a lot of new things to work with from an engineering standpoint, and getting the chance to interact with Sena as a client was huge, too,” he said. “There’s really not a class that teaches you how to interact with a person who has their own particular wants, ideas and capabilities. That experience will definitely be useful in the future.”

Shared purposes, different approaches

“Some people might think engineering and arts are very different, but artists and engineers kind of have a shared purpose,” Gavric said. “They create things. They bring things into existence, and have ideas and concepts that they want to make. The difference lies in medium and motive. An engineer might design a circuit board to save a life, while an artist might paint a picture to change a life.”

“Working with Sena, I kind of opened up to ‘why are we doing this this?’ Oh, it’s for the aesthetic, or it’s for trying to get the point across.”

Gavric admits, “There’s no way I ever thought I’d be working on a robot for an art project.” But even before Creston finished presenting her concept sketches to the Robotics Club, he was hooked.

“It intrigued me immediately as an interesting concept and totally something new. There was a lot of back and forth on what we could do with the given technology and funding, and a lot of compromises, abstractions and problems that were solved. It was a rare opportunity. I’m glad I did it.”

Loeffler especially appreciated the chance to think outside the box.

“I really enjoyed the opportunity to collaborate and come up with different ways to solve a problem,” he said. “I think we’re fairly close to what Sena originally envisioned, with the aesthetic and the function she was looking for, and that’s very satisfying.”

The interactive art machine projects encouraged the engineering students to consider their role as engineer, inventor, creator and artist, Creston said. As they grew comfortable working on art projects and expressing their own creative ideas, they sought new collaborations with artists and invited them to participate with the Robotics Club.

Some of the rising engineers began working with fine art students on interactive media projects and even created an interactive art installation of their own, called Lux Flux. The large-scale ceiling installation was designed to sense when a viewer entered a darkened hallway and to send a river of light shooting along the ceiling.

“The project was completely collaborative with a fluid crossover between artists and engineers filling in the rolls of conceptualizers, designers and technicians as needed,” Creston said. “It was beautiful to see.”

Creston is now working with a team of mechanical engineering design students to develop their collective senior year project. Her creative and scholarly work has received financial support from the WSU Office of Academic Affairs, the Department of Fine Arts and the School of Engineering and Applied Sciences, as well as a chancellor’s seed grant to provide tools and materials and a project grant from .

The interdisciplinary projects align with the  goal of improving education. They further the University’s  efforts by delivering innovative teaching, community outreach and transformative student experience.

Photos and  by Maegan Murray, ���سԹ� marketing and communications