Edinburgh-Leeds collaboration produces first ever 3D-printed tongue surface
Scientists from the Universities of Leeds and Edinburgh including Dr. Rik Sarkar have created the first ever 3D-printed synthetic soft surface that replicates the human tongue.
The ‘biomimetic tongue’ replicates the highly complex surface design of the human tongue, mimicking the topology, elasticity and wettability in order to accurately emulate how food and saliva interacts with the tongue. The team of scientists took digital scans of human tongues to 3D-print the synthetic surface, opening new possibilities for testing the oral processing properties of food, nutritional technologies, pharmaceuticals and dry mouth therapies.
The unique surface of the human tongue has hundreds of small bud-like structures called papilla, producing a roughness that contrasts with the softness of the tongue’s tissue. Together, these distinct textures create a complex landscape that defines the human tongue and is difficult to replicate using synthetic materials. The team tackled this difficulty by imitating the structure and distribution of two types of papillae found on the tongue’s surface, a crucial step in recreating the tongue’s mechanical friction, and sensing abilities.
The project is led by the University of Leeds and is a collaboration with the University of Edinburgh. LFCS Deputy Director Dr. Rik Sarkar, a co-author of the research, played a key role in recreating real tongue surfaces and designing artificial ones. Rik led the use of computer science and data science in the project, employing an approach that could be applied in other areas of biological and biomedical research in future.
We used computation and probability to understand biology at microscopic scales. With surface reconstruction techniques applied to 3D scans of micro-metre resolutions, we were able to digitally recreate and observe the fine features of real human tongue surfaces. We then created artificial 3D models of surfaces using CAD technologies, and verified experimentally that they show similar physical properties to natural surfaces.
Using probabilistic analysis, we were able to show that the distribution of papillae is an important aspect of the tongue surface, and it determines the accuracy of mechanical sensing. We devised “collision probability” as a metric for sensing quality, and simulations showed that the structure of human tongue makes it highly sensitive. Interestingly, the sensitivity of real papillae distribution resembles that of random designs. This approach can be applied to gain insights in other areas of biology.
With more technology becoming available at microscopic scales and generating highly detailed data, we can use computational methods and data science to gain new insights in biology and medicine. A combination of machine learning, 3D modelling and 3D printing will be the key to detailed understanding and reconstruction of biology.
The 3D-printed silicon structure will provide unique insight into how fluids interact with the tongue within the oral cavity, leading to new insights into how the biomechanics of the tongue influence the way we eat and talk. The artificial surface could be used for a variety of applications, from screening food and beverages to aiding research into orally-administered medication and dry mouth therapies.
The biomimetic tongue could be used in place of expensive and time-consuming human trials, accelerating the development process of newly designed products. This is particularly beneficial in light of Covid-19, as social distancing poses new challenges for human trials and consumer tests. By reducing manufacturers’ reliance on human taste testers, the synthetic tongue overcomes many obstacles and speeds up the screening process for new products.
We believe that fabricating a synthetic surface with relevant properties that mimics the intricate architectural features, and more importantly the lubricating performance of the human tongue is paramount to gaining quantitative understanding of how fluids interact within the oral cavity.
Ultimately, our hope is that the surface we have designed can be important in understanding how the biomechanics of the tongue underpin the fundamentals of human feeding and speech.
Read the paper in ACS Applied Materials and Interfaces