This paper presents the development of a new type of skin-like tactile pressure sensor array. The sensor array is scalable, flexible and stretchable and can measure pressure up to 250 kPa within 30% stretching rate without damaging its mechanical structure. It can also conform to irregular three-dimensional surfaces. The sensor array consists of three layers. The top and bottom layers are formed by the array of parallel conductive strips made of silver nanowires (AgNWs) embedded in polydimethylsiloxane (PDMS) thin films. The AgNWs/PDMS conductor strips are used as stretchable interconnections to transmit electrical signals. The middle layer is made of PDMS. This film is pre-molded with holes filling with cylinder-shaped conductive elastomer for pressure measurement. In this paper, the characteristic of the AgNWs/PDMS conductor strips as stretchable interconnections is studied. The piezoresistive properties of the sensels (one sensing element is called a sensel) were measured and discussed. The performance of the tactile sensor array under stretching was also tested. With the associated scanning power-supply circuit and data acquisition system, it is demonstrated that the system can successfully capture the tactile images induced by objects of different shapes. Such sensor system could be applied on curved or non-planar surfaces in robots or medical devices for force detection and feedback.
Bibliographical noteFunding Information:
This project is supported by the Strategic Seed Grant and the Vice Chancellor Research Grant of the University of Minnesota Duluth . Haopeng Wang is under the support from China Scholarship Council (CSC). The authors acknowledge the support from the Nanofabrication Center on the Twin Cities campus and the Control Lab on the Duluth campus of the University of Minnesota. The authors would like to thank Mr. Shailabh Kumar in Laboratory of Nanostructures and Biosensing at University of Minnesota Twin Cities. Special thanks to Dr. John Duetsch of Essentia Health – St. Mary's Hospital in Duluth MN for the support of this project.
Copyright 2013 Elsevier B.V., All rights reserved.
- Cylinder-shaped sensing elements
- High stretchability
- Pressure sensor array
- Silver nanowire interconnection