Interested in a career in engineering? Check out the ABET-accredited and nationally recognized 厙ぴ勛圖 engineering programs at��tricities.wsu.edu/engineering.

By Maegan Murray, 厙ぴ勛圖

RICHLAND, Wash. ��� A team of Washington State University Tri-Cities student mechanical engineers partnered with Washington River Protection Solutions (WRPS) to design a prototype of an instrument that could one day be implemented to assess the exact location, amount and arrangement of solid radioactive waste in Hanford tanks.

The device could solve a significant challenge out at the site, providing engineers and scientists at Hanford with a three-dimensional and much more reliable picture of the layout of solid waste. The device would allow them to better assess and prepare for situations at the site in the future, as compared with their current methods.

Currently, WRPS use devices that measure only one location in the tanks. They use either a sludge weight or other device that must sink down to the bottom of the liquid level of the waste in the tanks to determine the level of the solid waste. The current devices, however, do not provide information about the solids level at other locations in the tanks, the students said.

For their senior design capstone project, the student group, comprised of Bryan Chronister, Tanner Reyff, Rayce Barnes and Tomokazu Hager, designed a deploying system known as SLIM, or Solid Liquid Interface Monitor, that resists radioactive contamination and decay, and can be telescoped to different depths of the tank that uses a sonar device to get an accurate picture of the tank. The device could be left in the tanks and serve as a long-term solution in creating a reliable picture of the placement of the waste in the tanks, Reyff said.

���Currently, we have a 35-foot design from grade level, which is ground level, where it is submerged into the liquid level of the waste, and takes about five minutes to do a full scan of the tank with the sonar device,��� Hager said. ���Essentially, it creates a topographical scan of the full tank, which can be used for a range of future uses out at the Hanford Site.���

Developing the design

The student group spent their first semester developing four different designs, which they consolidated into one seamless design.

The team���s final design uses a winch to lower a telescoping tube into the supernatant, or liquid waste, that contains an existing sonar device that has been proven to withstand radioactive exposure. The tubing is encapsulated in a chamber that protects the outside environment from radioactive contamination. When the device is removed, it has a high-impact spray system that washes the tubing as it is being removed and also further reduces potential for contamination.

���We created a rigid design that provides control to the depth that is required and a stable insertion that would produce an accurate image of the solid waste within the tanks,��� Reyff said. ���The goal was to minimize the amount of radiation exposure that is also remotely operated.���

Supporting students to invest in the future

WRPS��� primary goal is to reduce the environmental risk posed by 56 million gallons of radioactive and chemical waste stored in 177 underground tanks at the Hanford Site that dates back to as early as World War II. The organization partners with WSU to develop technology to support that mission, as most technology must be specifically tailored to their needs due to the unique origins of the site as the home of the first large-scale nuclear reactor in the world.

Kayle Boomer, manager of the Technology Management and Field Solution group with WRPS��� Chief Technology Office, said he is impressed with the student���s design and that is has potential for out at Hanford.

���The team worked well together,��� Boomer said. ���They were very diligent and tried to ensure that the design addressed as many design requirements as possible. The other Hanford engineers working with them thought they were developing a workable design for the tank farm.���

WRPS provided the student group, as well as one additional student engineering group, with a total of $10,000 to develop prototypes that could one day be applied out at the Hanford Site. The other student group, which is comprised of students Anthony Jenkins, Melissa Rivas, Oleg, Tyshchuk and Michelle Wheeler, developed a device to sample any interface within the Hanford tanks.

���It was a great experience working with the WSU senior engineering students on their senior design project,��� said Jon Barnes, design services engineer for WRPS.�� ���Their energy and creativity was infectious. I���m hoping I���ll see them again in the engineering work world, and perhaps get a change to work together as peers.���

Jason Vitali, chief technology officer for WRPS, said the solutions identified by the students during their capstone project are extremely creative, thorough, and have the potential for resolving some of the challenges they encounter in the high-hazard environment.

���It is important that the students continue to tackle real-world challenges during their education so they are able to transition after school and make contributions early in their professional careers,��� he said.

 

Interested in a career in engineering? Check out the ABET-accredited and nationally recognized 厙ぴ勛圖 engineering programs at��tricities.wsu.edu/engineering.

By Maegan Murray, 厙ぴ勛圖

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 P繹tschke and Amir Ameli, recently published their findings in Polymers, an MDPI research journal.

Varied potential and recyclable

Ameli, 厙ぴ勛圖 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.