Table 1 Design parameters for the UroSleeve with the integrated antenna and pressure sensor as well as the external reader antenna used – σ: internal residual stress, E: Young’s modulus, ν: Poisson’s ratio, ε: dielectric permittivity R: DC resistance, L: inductance, fr: reflectance peak of the external reader antenna
From: Ureteral stent sleeve for early detection of hydronephrosis
Parameter | Size [µm] | Relevant parameters |
|---|---|---|
Tesla-valve enabled touch mode capacitive pressure sensor | ||
Sensor chip | ||
Width | 870 | |
Length | 3200 | |
Substrate thickness | 500 | |
Sensor membrane | σ 26 MPa | |
Radius | 250 | |
Au thickness | 2.85a | E 78 GPa, ν 0.44 |
Ti adhesion layer thickness | 0.02 | E 116 GPa, ν 0.32 |
Parylene C thickness | 4.6 | E 2.76 GPa, ν 0.40 |
Sensor gap (before deflection) | 2.8 | |
Sensor dielectric | ||
Sensor dielectric Si3N4 thickness | 0.275 | ε 9.7b |
Tesla-valve channels | 4 Channels/Cavity | |
Overall length | 178 | |
Overall width | 420 | |
Channel entrance width | 10 | |
UroSleeve 9 loop spiral antenna | R 1.4 ohm, L: 1.97 µH @ 15.1 MHz, fr 18.1 MHz | |
Length | 50,000 | |
Outer spiral width | 8270 | |
Inner spiral width | 2110 | |
Cu Line width | 200 | |
Cu Line thickness | 70 | |
Polyimide substrate thickness | 25 | |
Assembled bend curvaturec | 2790 | |
External reader 10 loop inductor | R 0.1 ohm, 4.5 µH @ 16.7 MHz, fr 28.5 MHz | |
Overall length | 50,000 | |
Overall width | 8000 | |
Wire thickness | 510.6 | 24-gauge magnetic wire |