Robotics team finds artificial fingerprints improve tactile abilities

September 21, 2011 by Bob Yirka, report
Schematic of the indentation process. (a) Flat surface being applied to the ridged skin cover. (b) Curved surface being applied to the ridged skin cover. Image credit: DOI:10.3390/s110908626

( -- Over the past couple of decades, many people in and out of the science community have watched the steady progress being made in robotics. It’s an exceptionally interesting field due to the anthropomorphic nature of the results. Each new step brings such machines closer to emulating us even as we look forward to the next step. One interesting thing about robotics is that certain areas seem to be advancing faster than others. Robot arms for example are old news, new research is focused more on hand movements. And has advances in hand movements have been made, more research has come to focus on finger movements and finally tactile sensations. Now new work by a trio of researches from the National University of Singapore describe in their paper published on the preprint server arXiv, how affixing artificial fingerprints to robot fingers can increase tactile "sensation" allowing such a robot to discern the differences in curvature of objects.

As with many areas of science, even the seemingly simple stuff turns out to be quite complicated on closer view. The human fingertip for example, covered with skin unlike that of any other body part, has raised ridges that allow people to feel the difference in texture between wood and metal or silk and linen. It can also detect temperature, and as it turns out, is also involved in figuring out the curvature of objects that are touched. Consider for example, the keys on a cell phone, or a television remote control. It’s these kinds of abilities that Saba Salehi, John-John Cabibihan and Shuzhi Sam Ge are trying to emulate in their lab in Singapore. To begin, they’ve started with the easiest of the bunch, trying to figure out if artificial fitted on a hand can tell how roundish an object is.

To find out they built a touch sensor comprised of a base plate, embedded sensors and a raised ridged surface; all on a 4mm square. They then set about testing the simple sensor in a variety ways to see if they were able to sense things with it in different ways, specifically as it was applied to flat, edged and curved objects. They also built an identical sensor except that the raised portion was flat instead of ridged, to serve as a control.

They found that the raised sensor did indeed provide more feedback (resonance) information than the one with the flat surface, so much so that they were able to tell the difference in the three types of objects with 95.7% accuracy.

Undoubtedly, more research will be done in this area by this group and others, and perhaps very soon, robot fingertips will become just as sensitive, if not more, than our own, leading to a whole new generation of gentler robots, able to perform tasks with both dexterity and a deft touch.

Explore further: HIRO III lets you feel what you see on screen (w/ Video)

More information: Artificial Skin Ridges Enhance Local Tactile Shape Discrimination, Saba Salehi, John-John Cabibihan, Shuzhi Sam Ge, arXiv:1109.3688v1 [] DOI:10.3390/s110908626

One of the fundamental requirements for an artificial hand to successfully grasp and manipulate an object is to be able to distinguish different objects' shapes and, more specifically, the objects' surface curvatures. In this study, we investigate the possibility of enhancing the curvature detection of embedded tactile sensors by proposing a ridged fingertip structure, simulating human fingerprints. In addition, a curvature detection approach based on machine learning methods is proposed to provide the embedded sensors with the ability to discriminate the surface curvature of different objects. For this purpose, a set of experiments were carried out to collect tactile signals from a 2 times 2 tactile sensor array, then the signals were processed and used for learning algorithms. To achieve the best possible performance for our machine learning approach, three different learning algorithms of Na"ive Bayes (NB), Artificial Neural Networks (ANN), and Support Vector Machines (SVM) were implemented and compared for various parameters. Finally, the most accurate method was selected to evaluate the proposed skin structure in recognition of three different curvatures. The results showed an accuracy rate of 97.5% in surface curvature discrimination.

via ArXiv Blog

Related Stories

HIRO III lets you feel what you see on screen (w/ Video)

July 2, 2010

( -- Researchers in Japan are developing a new touch screen system, the HIRO III, that incorporates a robot hand that could offer a new way of simulating the touching of virtual objects and receiving feedback ...

Underwater robot with a sense of touch

May 4, 2009

( -- Maintenance of offshore drilling rigs or underwater cables, taking samples of sediment - underwater robots perform a variety of deep-sea tasks. Research scientists now aim to equip robots with tactile capability ...

Robots get an artificial skin

July 1, 2010

Robots are breaking barriers: Long banished behind steel barriers, they are entering new fields of application such as the manufacturing, household and healthcare sectors. The requisite safety can be provided by a tactile ...

Researchers unveil whiskered robot rat

June 30, 2009

A team of scientists have developed an innovative robot rat which can seek out and identify objects using its whiskers. The SCRATCHbot robot will be demonstrated this week at an international workshop looking at how robots ...

Scientists develop sensitive skin for robots

June 29, 2011

Robots will soon be able to feel heat or gentle touching on their surfaces. Researchers at Technische Universitaet Muenchen are now producing small hexagonal plates which when joined together form a sensitive skin for "machines ...

Why Do We Have Fingerprints?

April 4, 2009

( -- Unlike most wrinkles on our bodies, which appear due to bending and stretching of the skin, fingerprints aren't the result of repeated motion. Each of us is born with a unique set of them, although scientists ...

Recommended for you

AI and 5G in focus at top mobile fair

February 24, 2018

Phone makers will seek to entice new buyers with better cameras and bigger screens at the world's biggest mobile fair starting Monday in Spain after a year of flat smartphone sales.

Google Assistant adds more languages in global push

February 23, 2018

Google said Friday its digital assistant software would be available in more than 30 languages by the end of the years as it steps up its artificial intelligence efforts against Amazon and others.


Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Sep 21, 2011
The more I learn about sensors, the more I wonder whether they can lead of a world in which common sense prevails. To see what I mean, Google: common sensor directory
not rated yet Sep 21, 2011
I wonder if they will find an optimum topology ? Would it be like patterns in human fingerprints, or..
not rated yet Sep 21, 2011
I wonder if they will find an optimum topology ? Would it be like patterns in human fingerprints, or..

If they did it would shoot any sort of 'intelligent design' argument in the foot.
1 / 5 (1) Sep 21, 2011
I wonder if they will find an optimum topology ? Would it be like patterns in human fingerprints, or..

If they did it would shoot any sort of 'intelligent design' argument in the foot.

How so?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.