Journal: Sensors (Basel, Switzerland)

Article Title: Low Temperature Adhesive Bonding-Based Fabrication of an Air-Borne Flexible Piezoelectric Micromachined Ultrasonic Transducer

doi: 10.3390/s20113333

Figure Lengend Snippet: The FEA of the PMUT using COMSOL Multiphysics 5.3. ( a ) Simulation model; ( b ) vibration mode shape at the resonant frequency of 202.58 kHz; ( c ) the chart of the admittance.

Article Snippet: The acoustic-piezoelectric interaction, frequency domain multiphysics interface was adopted in COMSOL 5.3.

Techniques:

Journal: Sensors (Basel, Switzerland)

Article Title: Low Temperature Adhesive Bonding-Based Fabrication of an Air-Borne Flexible Piezoelectric Micromachined Ultrasonic Transducer

doi: 10.3390/s20113333

Figure Lengend Snippet: The simulation results of PVDF based monolayer structure. ( a ) Simulation model built in COMSOL Multiphysics 5.3; ( b ) vibration mode shape at the resonant frequency of 126.16 kHz.

Article Snippet: The acoustic-piezoelectric interaction, frequency domain multiphysics interface was adopted in COMSOL 5.3.

Techniques:

Journal: Science Advances

Article Title: Autonomous push button–controlled rapid insulin release from a piezoelectrically activated subcutaneous cell implant

doi: 10.1126/sciadv.abm4389

Figure Lengend Snippet: ( A ) Upon membrane depolarization of engineered electro-sensitive cells constitutively expressing the channels Cav1.2 and K ir 2.1 and a synthetic Proinsulin construct, the intracellular calcium concentration is increased, which drives the release of vesicle-stored insulin. ( B ) Illustration of the prototypic piezoelectric module. The electrodes are connected to the top and bottom sides of a silver-coated PVDF film, providing positive and negative charges, respectively. ( C and E ) Scheme and image of the stimulation cell culture multiwell plate with electrodes aligned vertically in relation to the cell monolayer. ( D and F ) Scheme and image of stimulation cell culture inserts and multiwell plate with electrodes aligned horizontally in relation to the cell monolayer. Cells were cultured on a porous membrane inside inserts, with one electrode placed above and one below the cell monolayer to generate an electric field across it. For both vertical ( G ) and horizontal ( H ) electrode configurations, piezoelectrical pulses were produced for 3 min at 1 Hz by finger-pressing a piezoelectric module with a 52-μm PVDF film placed on human skin to allow sufficient deformation. Cells were also either nonstimulated or treated with 40 mM KCl (chemical depolarization) as negative and positive controls, respectively. Insulin expression level was measured in culture supernatant samples collected after 3 min of stimulation. Data are means ± SEM; n = 4. Statistical analysis was done with a two-tailed t test. ns, not significant; *** P < 0.001.

Article Snippet: The device contains a conductive cell culture chamber, a 28-μm PVDF film–based piezoelectric module (catalog no. 11028362-00, TE Connectivity), and a 3D-printed polylactide reinforcement ring.

Techniques: Membrane, Expressing, Construct, Concentration Assay, Cell Culture, Produced, Two Tailed Test

Journal: Science Advances

Article Title: Autonomous push button–controlled rapid insulin release from a piezoelectrically activated subcutaneous cell implant

doi: 10.1126/sciadv.abm4389

Figure Lengend Snippet: ( A ) Schematic representation of the device. The cell chamber is delimited by two porous membranes, with the bottom one also coated with platinum (Pt). A reinforcement ring is placed between the piezoelectric module and the conductive cell chamber. The piezoelectric module is linked by Pt wires to the conductive cell chamber, which encases engineered electro-sensitive cells. The conductive chamber allows diffusion of nutrients and therapeutic protein in and out of the device, as well as protecting the cells from immune system attack. ( B ) Pictures of the (i) top and (ii) bottom sides of unfolded and folded devices. The cells are injected into the cell culture chamber via a port in the reinforcement ring, followed by heat sealing of the porous membrane. Piezoelectric voltage output generated by finger-pushing the piezoelectric module on different materials. ( C ) Output voltage generated by periodically finger-pressing PVDF film–based piezoelectric modules of 28 and 52 μm thickness on top of human skin (applied pressure, around 1 kPa). ( D to F ) Voltage generated from piezoelectric module placed above 0.5 mm (D), 1 mm (E), and 2 mm (F) reinforcement rings. ( G ) Insulin secretion by electro-sensitive cells upon electrostimulation by finger-pushing the button-like implant for 3 min at 1 Hz. Nonstimulated and KCl-stimulated cells were used as negative and positive controls, respectively. ( H ) Insulin secretion kinetics. Electro-sensitive cells were stimulated for 30 min by finger-pushing and insulin levels in the cell chamber were analyzed by ELISA. Data are means ± SEM. Statistical analysis was done with a two-tailed t test ( n = 3). *** P < 0.001.

Article Snippet: The device contains a conductive cell culture chamber, a 28-μm PVDF film–based piezoelectric module (catalog no. 11028362-00, TE Connectivity), and a 3D-printed polylactide reinforcement ring.

Techniques: Diffusion-based Assay, Injection, Cell Culture, Membrane, Generated, Enzyme-linked Immunosorbent Assay, Two Tailed Test