Salamanders, origami and algorithms: load cells in university research

At the Load Cell Shop, we supply numerous university departments with a wide range of load cells for research projects, all year round. While most university students will have already settled into their summer jobs and graduates ate busy applying for job positions, university research doesn’t just stop for the holidays.

So, what are the projects that university-based researchers across the world are working on that includes load cells? We’ve been taking a look at some recent examples.

The art of lifting

The New Museum for Western Australia is being constructed with the aid of the Roborigger, developed by Tensa Equipment, which

“Significantly improves worksite safety by allowing riggers and dogmen to control loads wirelessly from a safe distance. The Roborigger device uses inertial forces to accurately rotate and orient crane loads, eliminating the need for workers to use taglines or to be in close proximity to the load during the lifting and lowering phases.”

The device includes a camera and a load cell, so that all data from a lift is available in real time, including the load’s weight, location, status and an image of the load itself. As the article in Cranes Today magazine explains:

“Tensa has.. been collaborating closely with Curtin University researchers, who developed the bespoke algorithm for Roborigger control.”

 

Generating electricity as you walk

This innovation brings a whole new meaning to power walking! A team of researchers from the Mechanical and Materials Engineering and Ingenuity Labs at Queen’s University worked on a backpack that harnessed energy created from the side to side motion of the normal human gait. As an article in Tech Xplore explains:

“Biomechanical energy harvesters are devices that are attached to or carried by humans and generate electricity by harvesting energy from movements.The device consists of a weight attached to the top part of a pendulum, which swings back and forth as a person is walking.”

The load cell was sited between the load carriage device and the backpack frame to measure ass relative M–L displacement as follows:

“Device interaction force and moments were measured over the last 2 min of each trial using a 6 d.f. load cell. Force and moment were sampled at 1000 Hz and filtered using a low-pass zero-phase Butterworth filter with cut-off frequency of 16 Hz. The peak M–L and vertical interaction force, and frontal plane interaction moment, were defined as the maximum magnitude of force/moment over each stride, averaged over the last 2 min of each condition. The interaction force measured by the load cell was assumed to be the interaction force experienced by the user.”

The team found that by adding a 20lbs weight, the backpack could generate sufficient energy to power a GPS handset, and with 55lbs, could power a smart phone.

 

A mechanobiological approach to wound management

A team combining expertise from Harvard University, University of California (San Francisco, and Berkeley) and McGill University Montreal investigated how dressing for wounds might be mechanically active. They developed and tested:

“Thermoresponsive tough adhesive hydrogels that combine high stretchability, toughness, tissue adhesion, and antimicrobial function. They adhere strongly to the skin and actively contract wounds, in response to exposure to the skin temperature.”

Load cells were used to shear test the dressings:

“Pure-shear tests were performed. A (testing) machine with a load cell maximum of 50 N was used to apply unidirectional tension on specimens (80 mm by 5 mm by 1.5 mm). The strain limit was defined as the ratio of the extension of the specimen upon rupture to that of the undeformed specimen.”

 

Why do salamanders live where they do?

We love this one! Trevor Chapman, a doctoral student in biomedical sciences at East Tennessee State University has worked out the optimum “Goldilocks’ habitat for salamanders – not too hot, not too cold, and just the right humidity. According to a report in the Johnson City Press:

“Chapman found a way to induce varying temperatures, moisture levels and other factors in each of the chambers. The floor of each chamber is equipped with a load cell that is connected to sensors that record the animal’s movement between the four chambers.

It allows consistent recording of their behavior without having to disturb them. It looks like some kind of Frankenstein experiment, but it works, and it’s just such a novel system. … Most folks are only looking at one variable, and it’s usually a visual observation system, so you’ve got to videotape it and go back and look at it. This device records everything, and you can just go back and look at the data and tell which of the chambers the animals have been in.”

 

Impact mitigating system based on origami

The principles of origami, the ancient art of paper folding and modelling, have been used by a team of researchers (to design impact mitigation systems that don’t rely on material dampening, fracture of plasticity. According to the team:

“We are able to design an origami-based metamaterial that can form rarefaction solitary waves. Our analytical, numerical, and experimental results demonstrate that this rarefaction solitary wave overtakes initial compressive strain waves, thereby causing the latter part of the origami structure to feel tension first instead of compression under impact.”

The load cells were used to test the prototype polygon unit cells made from laser cut paper and multiple folds.

 

Load cells for university research

If you require load cells for any type of research and testing, call us first. We are UK based, and design and manufacture nearly all of our load cells. We can help design bespoke systems and solutions to your requirements, and even create unique load cells just for you. For more information, or to talk through your requirements, call or email. We’re here all summer!