Case studies – Materials and Adhesives

Massey researchers have expertise in smart robot design and industrial automation, and reconfigurable, flexible, hard and soft robotic systems. They are working on indoor and outdoor autonomous robots for industrial applications including agriculture and forestry, and intelligent control system design via smart sensing, machine learning, vision, bio-signal, embedded programming, and wireless communication. They work closely with business and organisations to develop robots to meet industry needs.

The challenge

A humanoid robot was developed at the School of Engineering and Advanced Technology, Massey University, New Zealand, for implementing and evaluating dynamic gait algorithms. Force sensors were placed on the bottom of the feet of the robot to provide feedback for the control system. The use of resistive force sensors was investigated as an inexpensive and lightweight alternative to multi-axis force/torque sensors.

The research

However, resistive force sensors have a more limited accuracy and response time. Sensors from three companies were tested: Sensitronic, Interlink, and Inaba Rubber. The sensors were tested with a TA.XTplus texture analyser, looking for repeatability of response, drift, and response time to both application and removal of the force. An inverting op-amp was used to convert the force measurement of the sensor to an output voltage, which was read by an oscilloscope. The force measurements from the texture analyser and the voltage output from the oscilloscope were recorded digitally.

The outcome

The data obtained from the measurements was analysed and the potential uses and limits of the sensors as feedback mechanisms in a bipedal humanoid robot were able to be determined.

The University of Zagreb is the largest Croatian university and the oldest continuously operating university in the area covering Central Europe south of Vienna and all of Southeastern Europe.

The challenge

Researchers at the School of Medicine at the University of Zagreb used their Texture Analyser to study the biomechanical properties of bones from rats treated with sevelamer. Sevelamer has been used for many years to lower high blood phosphate levels in patients who are on dialysis due to severe kidney disease. Dialysis can leave high phosphate levels in the blood, and bringing these levels down using Sevelamer can help keep bones strong, prevent the unsafe build-up of minerals in the body, and possibly decrease the risk of heart disease and stroked that can result from high phosphate levels.

The research

With samples from rats given Sevelamer for 25 weeks on a standard diet, three-point-bend tests on the TA.HDplus Texture Analyser were used to determine the mechanical properties of the cortical bone of the mid-shaft femur, while an indentation test was used to determine the mechanical properties of cancellous bone in the marrow cavity of the distal femoral metaphysis.

The outcome

Parameters analysed included: maximum load, stiffness, energy absorbed, toughness and ultimate strength and highlighted that sevelamer significantly improves bone biomechanical properties, mainly affecting trabecular bone quality.

Tom's Hardware is the leading destination for tech enthusiasts of all skill levels. Whether you're building a PC, buying a laptop or learning how to create robots with your kids, they have comprehensive editorial resources and a vibrant expert community to help you on your journey.

The challenge

Tom’s Hardware wrote about their process for developing a method for testing mechanical keyboard switches using the TA.XTplus Texture Analyser. Tom’s Hardware is the exhaustive, trusted resource for early adopters and experts who are passionate about technology. They create comprehensive product reviews, expert technical analysis and how-to guides, and the latest news, peppered with unique insight.

The research

During an objective test on a keyboard, the switches are primarily under investigation, and these are actuated by pressing keys. The key’s force-distance profile gives information on the force required to overcome the ‘tactile bump’, as well as the distance at which this force peak occurs. Electronic actuation can happen at any point on the key’s travel.

The outcome

For this guide, Tom’s Hardware “settled on a test speed that captures enough of the key feel for an operator to draw some conclusions. The press is two seconds (the release is a little faster). Each test run produces the force curve of one switch and collects around 100 data points per millimetre of travel, total. Because there are over 100 individual keys on a full-size keyboard, then, testing a keyboard with switches that have 4mm of travel generates approximately 40,000 data points.” Read in detail about their procedure for testing mechanical keyboard switches.

Tor Vergata University is the second public university of Rome providing high quality education for international students.

The challenge

Art restorers face many challenges relating to minimising damage while they work.

The research

Scientists at Tor Vergata University characterised hydrogels using their TA.XT2 Texture Analyser for their published work "Cleaning of paper artworks: development of an efficient gel-based material able to remove starch paste".

The outcome

These samples were a type of rigid hydrogel used for a simple and localised removal of starch paste from paper supports. This overcame many of the problems faced by restorers minimising damage through a controlled release of water to the artwork) and a simple and non-invasive application and removal compared with old fashioned water-based methods. In this context, experiments were carried out applying Gellan hydrogel carrying α-amylase enzyme on several paper samples soiled with starch paste. To assess the cleaning efficacy of the proposed hydrogel, a multidisciplinary approach was used by means of Texture Analysis, spectroscopic techniques, scanning electron microscopy, chromatographic analysis and pH investigations.

LG Electronics are focused on developing new innovations across the globe. They are committed to providing electronic products that help customers live better.

The challenge

LG have used their TA.XTplus Texture Analyser for many patent applications in the field of electronic product development. For electronic devices having an input controller provided with a touchscreen or a touch panel switch, a transparent conductive plastic film is used to achieve light weight and prevent cracking.

The research

An example of the film includes a film which includes a base of a polyethylene terephthalate (PET) film, and a conductive layer of indium tin oxide (ITO) formed on one surface of the base. The film is stacked on a conductive glass, a stiffener, or a decorative film via an adhesive layer. The adhesive layer requires various properties, such as durability which the Texture Analyser can assess by the degree of deformation over time after application of 1000gf to the adhesive film for 5 minutes.

The outcome

Their Texture Analyser has been invaluable to the publication of patents in the field of electronic product development.

Evonik Industries is the second largest chemicals company in Germany, and one of the largest speciality chemicals companies in the world.

The challenge

Evonik needed to develop a testing procedure to allow accurate and repeatable caking and flow assessment of their AEROSIL and SIPERNAT products which contained silica. By definition, these powders are much more free-flowing than standard powders and granules and even compressed samples are relatively unstable and easy to disturb when being loaded onto testing instrumentation.

The research

They developed a special rig which allows a prepared sample to be loaded onto their Powder Flow Analyser avoiding any potential damage to the compacted structure before the test begins. As a global supplier of specialty chemicals for the food, feed, pharmaceutical and chemical industries the new test allows the identification of the most appropriate flow agent for a particular application.

The outcome

This enabled the specification of addition levels to control clumping and crusting behaviour and to maintain free-flowing powders which are easier to handle and process.

The Food and Drug Administration (FDA) is responsible for protecting public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products, and medical devices; and by ensuring the safety of the US nation's food supply, cosmetics, and products that emit radiation.

The challenge

At the AAPS in 2008 researchers Shah, Tawakkul & Khan from the Division of Product Quality Research at the Food and Drug Administration presented their findings on the evaluation of powder flow by compendial and non-compendial methods, with help from the Powder Flow Analyser by Stable Micro Systems. The objective of their work was to carry out an evaluation of flow of pharmaceutical powders and granules. The understanding of their flow is crucial during mixing, packaging and transportation. Different grades and concentrations of magnesium stearate and granules prepared by various methods were used in a model formulation.

The research

Angle of Repose, Bulk & Tapped Density, Carr’s compressibility Index, and Hausner Ratio were the traditional Compendial methods employed whilst the Non-Compendial method of using a Powder Flow Analyser for the attribute measurements of Cohesivity Index, Caking Strength and Flow Stability were compared.

The outcome

The researchers successfully carried out an evaluation of flow of pharmaceutical powders and granules.

Tesa is one of the world’s leading manufacturers of self-adhesive product and system solutions for industry, professional craftsmen and consumers.

The challenge

The magnitude of tack force is a crucial parameter for tape manufacturers.

The research

Tesa uses their Texture Analyser in a large amount of patents applications. For example, using the probe tack method, the adhesive behaviour of a double-sided adhesive tape is characterised by means of a TA.XT2i Texture Analyser. In the method, a probe with cylindrical steel die is advanced vertically onto the adhesive at a predetermined test speed until a defined pressing force is reached, and, after a defined contact time, is removed again, once more at a predetermined speed. During this operation, the force expended for pressing or detaching, respectively, is recorded as a function of the travel.

The outcome

Similarly, their Texture Analyser is used to measure the degree of stretching, tensile strength, bond strength and stripping force of strippable systems.

Samsung is one of the world’s largest producers of electronic devices. Samsung specialises in the production of a wide variety of consumer and industry electronics, including appliances, digital media devices, semiconductors, memory chips, and integrated systems. It has become one of the most recognisable names in technology and produces about a fifth of South Korea’s total exports.

The challenge

In true Samsung fashion they reinvented the smartphone screen, pioneering new technologies and materials to create beautifully thin, multi-layered displays. Glass substrates or high hardness substrates have been replaced with films in optical display devices such as liquid crystal display devices and organic light emitting diode display devise. Thus, flexible display devices have now been developed with flexibility, which can be folded and unfolded. The devices have a structure in which window films are laminated on display elements and an optical clear adhesive film is intervened between. The usage, storage and preparation environments have become harsh and the variety of physical properties required by a flexible optical display have increased. In particular, the optical clear adhesive film needs to maintain its viscoelasticity property in wide temperature ranges and have excellent recovery properties.

The research

They used their TA.XTplus Texture Analyser to measure elongation by rolling the adhesive film to a specific sample size, fixing it to the Texture Analyser and stretching it to breaking point. In addition, a T-peel strength test and tensile recovery rate test were used and formula applied to obtain useful measurement parameters that characterise the physical properties of the films.

The outcome

Without the ability to measure these properties improved strength or flexibility cannot be quantified and therefore an understanding of the effects of material change or improvement cannot be obtained. With measurement comes the ability to develop the optimum product with its most desired performance. Find out more about Samsung’s patent development using their Texture Analyser.