| AVS 66th International Symposium & Exhibition | |
| MEMS and NEMS Group | Tuesday Sessions |
| Session MN-TuM |
| Session: | MEMS, BioMEMS, and MEMS for Energy: Processes, Materials, and Devices II |
| Presenter: | Hao Chong, Case Western Reserve University |
| Authors: | H. Chong, Case Western Reserve University S.J.A. Majerus, Louis Stokes Cleveland VA Medical Center J. Liu, Case Western Reserve University C.A. Zorman, Case Western Reserve University |
| Correspondent: | Click to Email |
A vascular graft is commonly used to bypass damaged blood vessels or to form an arteriovenous shunt for vascular access (e.g. for hemodialysis). Real-time monitoring of blood flow in synthetic grafts would provide early warning of graft failure to permit interventions such as angioplasty or graft replacement to avoid catastrophic failure. Based on biocompatible materials, we have developed a new type of flexible pulsation sensor (FPS) which is wrapped around a graft to monitor blood pressure and flow. The FPS uses Carbon Black (CB) dispersed in polydimethylsiloxane (PDMS) as a piezoresistive sensor layer, which is stencil printed on a structural PDMS layer. In this study, we analyze the strain transducer mechanisms on a vascular graft and show the linear and stable strain response of CB-PDMS composites from 0-50% strain. The material has a broader strain range than graft materials and a gauge factor of 5. In vitro testing of the FPS on a vascular graft phantom showed a robust, linear sensor output to pulsatile flows and pressures. The composite material shows excellent potential in biologic strain sensing applications where a flexible sensor with large maximum strain range is needed.