3D Biomimetic Tongue-Emulating Surfaces for Tribological Applications

Abstract

Oral friction on the tongue surface plays a pivotal role in mechanics of food transport, speech, sensing, and hedonic responses. The highly specialized biophysical features of the human tongue such as micropapillae-dense topology, optimum wettability, and deformability present architectural challenges in designing artificial tongue surfaces, and the absence of such a biomimetic surface impedes the fundamental understanding of tongue–food/fluid interaction. Herein, we fabricate for the first time, a 3D soft biomimetic surface that replicates the topography and wettability of a real human tongue. The 3D-printed fabrication contains a Poisson point process-based (random) papillae distribution and is employed to micromold soft silicone surfaces with wettability modifications. We demonstrate the unprecedented capability of these surfaces to replicate the theoretically defined and simulated collision probability of papillae and to closely resemble the tribological performances of human tongue masks. These de novo biomimetic surfaces pave the way for accurate quantification of mechanical interactions in the soft oral mucosa.

Saliva matters: Reviewing the role of saliva in the rheology and tribology of liquid and semisolid foods. Relation to in-mouth perception

“…PDMS is the most common material for the ball and plate used in the MTM; it is also hydrophobic, can adsorb saliva and is believed to bear a close resemblance to human oral surfaces because of its elastomeric nature (Bongaerts, Fourtouni, & Stokes, 2007). Recently, a 3D printed PDMS surface that imitates several features of the human tongue surface has been reported (Andablo-Reyes et al, 2020); the advantages of this material are that it not only mimics the wettability, roughness, and deformation of oral surfaces but also incorporates the topography of the tongue (papilla density). Although more results with this new material for food tribology applications are still to be seen, it seems highly promising.…”

Oral tribology: Providing insight into oral processing of food colloids

“…Oral tribology has a huge potential for designing biophysically informed food colloids in the future in a cost-effective manner, but effective mimicking of the complex features, deformability and motions of oral surfaces to perform tribological experiments and harmonization of such surfaces to answer specific questions are still needed to enable its widespread use. Although there has been growing interests in designing new tribometers with continual attempts to emulate oral tongue surface in terms of softness, wettability and roughness (Andablo-Reyes, et al, 2020;Bongaerts, et al, 2007;Carpenter, et al, 2019;Rudge, Scholten, & Dijksman, 2020;Sarkar, et al, 2017a;Taylor & Mills, 2020) using a variety of tribological or custom-made rheological set-ups or altering motions in the set ups (Andablo-Reyes, et al, 2020;Fuhrmann, Aguayo-Mendoza, Jansen, Stieger, & Scholten, 2020;Mo, Chen, & Wang, 2019;Tsui, Tandy, Myant, Masen, & Cann, 2016;Wang, Wang, & Chen, 2021), such designs and improvements in tribological set ups are considered to be beyond the scope of this article. We also do not cover salivary tribology or food-saliva interactions in this article as this topic has been extensively covered in recent reviews (Boehm, Yakubov, Stokes, & Baier, 2020;Mosca & Chen, 2017;Sarkar, Andablo-Reyes, Bryant, Dowson, & Neville, 2019a;Sarkar & Singh, 2012;Sarkar, Xu, & Lee, 2019b;Sarkar, et al, 2017b).…”

Food Oral Processing—An Industry Perspective

“…Currently missing from these systems are the simulation of the more complex roles of the tongue in oral processing including its interactions with products being consumed. Recent advances that could be incorporated into future systems include the development of a soft robotic tongue for studying in vitro swallowing systems ( 90 ) and 3D-printed soft biomimetic surfaces designed to replicate tongue topography, wettability, and tribological performance ( 91 ).…”