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Embedding Soft Material Channels for Tactile Sensing of Complex Surfaces - Mathematical Modeling

Research output: Contribution to journalArticlepeer-review

Original languageEnglish
Article number9209052
Pages (from-to)3172-3183
Number of pages12
Issue number3
Published1 Feb 2021

Bibliographical note

Funding Information: Manuscript received July 27, 2020; revised September 10, 2020; accepted September 12, 2020. Date of publication September 29, 2020; date of current version January 6, 2021. This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC) under Grant EP/R013977/1 and in part by the National Natural Science Foundation of China (NSFC) under Grant 51520105006. The associate editor coordinating the review of this article and approving it for publication was Dr. Emiliano Schena. (Corresponding author: Hongbin Liu.) Jian Hu, Junghwan Back, and Hongbin Liu are with the Faculty of Life Sciences and Medicine, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EU, U.K. (e-mail:;; Publisher Copyright: © 2001-2012 IEEE. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

King's Authors


Currently most of tactile array technologies is difficult to cope with three dimensional complex surfaces and there is an urgent need to develop tactile sensors that can provide a high-density integrated array on a surface of arbitrary shape. Our laboratory has been working on the development of a novel tactile sensing technique to solve this challenge, by 'Embedding Soft material into Structure ENabling Tactile sensing' of complex surfaces (ESSENT). This method creates sub-millimeter multiple channels filled with low compressibility elastic material. Tactile information is obtained by measuring the micro deformation of the soft material via projecting light to the material channel and measuring light reflection. However, the relationship between light reflection and soft material deformation is a complex function related to the geometry of reflective surface, elasticity of the soft channel and lighting conditions. To gain fundamental understanding of this new tactile sensing principle, we developed a mathematical model which is able to predict the precise deformation of the reflective surface of a soft material and provide the theoretical prediction of sensing sensitivity with respect to the lighting condition and the magnitude of the applied force. We demonstrated that the shape of soft material channel, the shape of reflective surface, as well as the location of light resource have significant influence on the sensor behavior.

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