A highly sensitive, low-cost, wearable pressure sensor based on conductive hydrogel spheres.
Wearable pressure sensing solutions have promising future for practical applications in health monitoring and human/machine interfaces. Here, a highly sensitive, low-cost, wearable pressure sensor based on conductive single-walled carbon nanotube (SWCNT)/alginate hydrogel spheres is reported. Conductive and piezoresistive spheres are embedded between conductive electrodes (indium tin oxide-coated polyethylene terephthalate films) and subjected to environmental pressure. The detection mechanism is based on the piezoresistivity of the SWCNT/alginate conductive spheres and on the sphere-electrode contact. Step-by-step, we optimized the design parameters to maximize the sensitivity of the sensor. The optimized hydrogel sensor exhibited a satisfactory sensitivity (0.176 ΔR/R0/kPa(-1)) and a low detectable limit (10 Pa). Moreover, a brief response time (a few milliseconds) and successful repeatability were also demonstrated. Finally, the efficiency of this strategy was verified through a series of practical tests such as monitoring human wrist pulse, detecting throat muscle motion or identifying the location and the distribution of an external pressure using an array sensor (4 × 4).
King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, COHMAS Laboratory, Thuwal 23955-6900, Saudi Arabia. gilles.lubineau@kaust.edu.sa.
Yanlong
Y
Tai
Matthieu
M
Mulle
Isaac
I
Aguilar Ventura
Gilles
G
Lubineau
D000464:Alginates; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008567:Membranes, Artificial; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods; D037742:Nanotubes, Carbon; D011093:Polyethylene Terephthalates; D017971:Tin Compounds
D000464:Alginates; D006603:Hexuronic Acids; D008567:Membranes, Artificial; D037742:Nanotubes, Carbon; D011093:Polyethylene Terephthalates; D017971:Tin Compounds; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C109984:indium tin oxide; D020723:Glucuronic Acid