Prof. Dr. David Franklin, head of the Associate Professorship of Neuromuscular Diagnostics, together with scientists from The University of Tokyo, has now developed an ultra-thin measuring sensor that can be directly attached to the skin of the fingertips. The so-called “nanomesh sensor” measures how fingers interact with objects and can thereby provide important statistical data for technological or medical applications.
The results were published in the “Science” journal (impact factor 41,845) with the title “Nanomesh pressure sensor for monitoring finger manipulation without sensory interference”. This publication also involved Prof. Dr. Gordon Cheng from the Chair of Cognitive Systems at the TUM Department of Electrical and Computer Engineering. The co-author Prof. Dr. Takao Someya from The University of Tokyo was a Hans Fischer Senior Fellow at the TUM Institute for Advanced Study (IAS) from 2017 to 2020. Among others, the research project was also funded by the IAS.
“The University of Tokyo, led by Prof. Someya, has been working on the concept of an ultra-thin pressure sensor,” explains Prof. Franklin. “Subsequently, the question arose as to how we can test whether this ultra-thin measuring sensor affects human sensation. This is where my Professorship came into play. It is not easy to demonstrate this effect, but in our laboratory, we have the means to do so.”
For the investigations, a two-micrometre-thick polymer film consisting of a total of four layers was applied to the fingertip. The first layer consists of polyurethane nanofibres, which acts as a passivation and support layer. This is followed by an ultra-thin layer of gold, an intermediate layer of polyurethane nanofibres coated with parylene and finally another layer of gold.
The effect of the sensor on human sensation was investigated with the help of 18 test participants. Their data confirmed that the sensors were imperceptible and would neither affect their ability to grasp objects via friction nor their perceived sensitivity if the same task had been performed without a sensor attached.
“This measurement sensor is now a new tool that we can use for studying neuroscience and motor control. Previous tools either affected human sensation or required rigid objects. Now, we can investigate what happens during natural movements when, for example, you want to find out how ripe a tomato is. We can gather accurate information and document the exact pressure exerted by the fingers or fingertips,” explains Prof. Franklin.
Prof. Dr. David Franklin
Associate Professorship of Neuromuscular Diagnostics
Georg-Brauchle Ring 60/62
phone: 089 289 24583
Text: Romy Schwaiger
Photo: Someya-Yokota-Lee Group/The University of Tokyo