There is increasing commercial interest in small-scale electricity generator applications that harvest energy from mechanical vibrations or linear motion. To address this interests researchers at UC Berkeley have developed a magnetic circuit architecture that has higher flux densities on the order of one Telsa across large functional air gaps. This circuit generates large induced voltages that can be easily rectified and stored to power wireless devices such as condition monitor sensors. This innovative circuit can be used to efficiently transduce any linear kinetic energy but is particularly attractive for small-scale applications because the magnetic circuit generates large induced voltages for overall device length scales on the order of millimeters and centimeters. The source of the kinetic energy that is transduced can come from coupling to mechanical motion mechanical vibration current carrying conductors fluid flows or pressure differences. Applications: The best applications for this magnetic circuit are small-scale electricity generators or energy transfer and high force short stroke actuators that benefit from linear control.
1) Magnetic flux loop entirely through permanent magnetic material enabling large air gaps with large functional magnetic fields 2) Coreless motors with high gap flux densities on the order of 1 Telsa 3) No low reluctance material is needed 4) High force constant and high force density