• Acoustic Characterization of Inhomogenous Layers using Finite Element Method 

      Bolstad, Per Kristian; Manh, Tung; Frijlink, Martijn; Hoff, Lars (Peer reviewed; Journal article, 2021)
      This study presents a finite element approach to estimate acoustic parameters of layers of arbitrary compositions using 2D and 3D models. In this approach the resonance frequency of a layer to be investigated is found by ...
    • Fabrication and Characterization of a Low-Frequency Array for a Hybrid PZT-CMUT Transducer 

      Siu, Hoi Yi (Master thesis, 2021)
      Piezocomposite materials consist of a periodic structure of active piezoelectric materials and passive polymer materials. Piezocomposite material is widely used in medical ultrasound transducers due to the advantages of ...
    • Impact of High Pressures on Au-Sn Solid Liquid Interdiffusion (SLID) Bonds 

      Bolstad, Per Kristian; Kuziora, Stephane; Nguyen, Hoang-Vu; Manh, Tung; Aasmundtveit, Knut; Hoff, Lars (Chapter, 2020)
      This paper investigates the influence of high pressure on Au-Sn solid-liquid interdiffusion (SLID) bonds formed by bonding Si substrates to dies of either lead-zirconate titanate (PZT) with high surface roughness or Si ...
    • Intermetallic bonding as an alternative to polymeric adhesives in ultrasound transducers 

      Bolstad, Per Kristian; Le, Anh Duy; Hoff, Lars; Manh, Tung (Peer reviewed; Journal article, 2019)
      Common ultrasound transducers utilize epoxy for bonding the active piezoelectric to the rest of the acoustic stack. This paper explores some of the potential benefits of replacing this soft epoxy layer with a harder ...
    • Ultrasound Transducers for High Pressure Environments Up to 1000 Bar 

      Bolstad, Per Kristian; Manh, Tung; Midtseter, Nils; Frijlink, Martijn Egbert; Hoff, Lars (Peer reviewed; Journal article, 2020)
      This paper studies the influence of high ambient pressure on ultrasound transducers where the piezoelectric layer is bonded to the acoustic matching layer by two different methods: Au-Sn solid-liquid interdiffusion and ...