Fabrication of a strain sensor for bone implant failure detection based on piezoresistive doped nanocrystalline silicon

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Alpuim P (Author) Other; Filonovich SA (Author) Other; Costa CM (Author) Other; Rocha PF (Author) Other; Vasilevskiy MI (Author) Other; Lanceros-Mendez S (Author) Other; Frias C (Author) Other; Torres Marques A (Author) FEUP; Soares R (Author) FMUP; Costa C (Author) Other

Journal

Title: Journal of Non-Crystalline Solids

Vol. 354

Pages: 2585-2589

ISSN: 0022-3093

Publisher: Elsevier

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ISI Web of Knowledge - 22 Citations

ISI Web of Science

Scopus - 13 Citations

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Scientific classification

CORDIS: Technological sciences

Other information

Authenticus ID: P-003-ZSN

DOI: 10.1016/j.jnoncryso1.2007.09.094

Abstract (EN): One common complication following total-hip-replacement arthroplasty - one of the most performed elective surgical procedures - is the loosening of the prosthetic stem and cup, responsible for more than 80% of non-successes. A combination of piezoelectric and piezoresistive materials in a sensing device for dynamical and quasi-static analysis of the implant internal environment is envisaged by the authors. In this paper, thin-film piezoresistive millimeter-long strain sensors fabricated on flexible plastic substrates using n- and p-type hydrogenated nanocrystalline silicon films with gauge factor GF similar to -30 and +20, respectively, are reported. A maximal value of GF = -43 is theoretically predicted for isotropic n-type multicrystalline Si. A sensor consists of an array of piezoresistors, each connected to a Wheatstone bridge-type external circuit, and to the control electronics. A sensitivity of 30 mV/mu m was achieved in sensors bearing both longitudinal and transverse orientations of the resistors relative to the strain direction. Used as a shape sensor the device was able to map the contour of the hip implant. Cell growth tests show that osteoblasts grow faster on P-doped nc-Si:H thin films than on the control sample. Genotoxicity tests show that cell DNA is preserved if cultured in contact with n-type nanocrystalline silicon.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5