This paper presents acoustic propulsion in air by synthesis jets produced by ultrasounds. Various ultrasonic air-borne propellers have been fabricated on 0.37-mm-thick commercial card piezoelectric speakers (APS2513S-T-R, 25.2 × 16.6 × 0.37 mm3 in size), and studied, with the propulsion force measured through a precision weight scale, as the orifice size, thickness, spacing between orifices, and number (in the orifice array) are varied. Also varied is the orifice depth profile, as the fabrication processes for the orifices produce varying profiles. Strongest acoustic propulsion of 5.4 mg is obtained at 66 kHz (far beyond audible range) with 14 × 14 orifice array made on a 0.1-mm-thick polyester plate (resulting in a propeller of 25.2 × 16.6 × 1.37 mm3 in volume and 500 mg in weight). The acoustic propulsion force, though 93 times less than the propeller weight, is capable of making the propeller jump and move laterally.
more »
« less
This content will become publicly available on June 26, 2024
Wireless Acoustic Airborne Jet Propeller
This manuscript presents airborne jet propulsion by audio sounds and ultrasounds through orifices formed by bulk-micromachining of a silicon wafer. The propeller is integrated with a small, printed circuit board (PCB) with a DC/DC converter, an oscillator, and a power amplifier, all powered by a 100F lithium-ion capacitor to make the propeller operable wirelessly. The peak propulsion force of the wireless propeller is measured to be 63.1 mg (or 618 mN) while the packaged wireless propeller’s weight is 10.6 g, including the drive electronics and adapter) when driven by 2.5kHz sinusoidal voltage with 21.4Vpp. A wired propeller (with 563 mg weight without adapter) is shown to high jump, long jump, wobbly fly, and propel objects. Also, the propeller is shown to work when driven by ultrasounds with a maximum propulsion force of 8.4 mg (82 mN) when driven by 20kHz, 20Vpp sinusoidal signal. Varying the frequency gradient of the applied sinusoidal pulses is shown to move the propeller to the left or right on demand to reach a specific location.
more »
« less
- Award ID(s):
- 2017926
- NSF-PAR ID:
- 10419599
- Date Published:
- Journal Name:
- Transducers '23, The 22nd International Conference on Solid-State Sensors, Actuators and Microsystems
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
This paper presents a wireless and stand-alone subminiature propeller based on acoustic propulsion for the underwater robotic applications. The acoustic propulsion is generated by a MEMS-based self-focusing acoustic transducer (SFAT), fabricated on 1-mm-thick lead zirconate titanate (PZT) substrate, and operated at its thickness mode resonant frequency of 2.32 MHz. A 100F lithium-ion capacitor (LIC) is used as a power source due to its high energy and power densities. A drive electronic circuit is implemented on a flexible printed circuit board (PCB) and delivers 30Vpp sinusoidal signal to the acoustic propeller. The completed system is 18 x 18 x 38 mm3 in volume and weighs 12.56 grams, resulting in a mass density of 1.020 g/cm3. The acoustic propulsion generated by the acoustic propeller is measured to be 18.68μN with the electrical power of 358.7mW consumed by the propeller. Both vertical and horizontal propulsions are demonstrated successfully in sodium polytungstate (SPT) solution.more » « less
-
This paper describes a subminiature underwater ultrasonic propeller with electrically controllability over its propulsion direction. Built on a 200-micron thick nickel-coated lead zirconate titanate (PZT) substrate, the propeller consists of 28 sectors of individually accessible Fresnel lens that are composed of Parylene air-cavity-reflectors on top of the frontside nickel electrode. A backside Fresnel air-reflector is added to prevent any propulsion from the backside that may cancel the propulsion from the front side. The fabricated propeller (4 x 4 mm2 in size and 37.5 mg in weight) is demonstrated to have control over its advancing direction when assembled on an air-filled capsule.more » « less
-
Miniature Magnetic Rotating Swimmers (MMRSs) are untethered machines containing magnetic materials. An external rotating magnetic field produces a torque on the swimmers to make them rotate. MMRSs have propeller fins that convert the rotating motion into forward propulsion. This type of robot has been shown to have potential applications in the medical realm. This paper presents new MMRS designs with (1) an increased permanent magnet volume to increase the available torque and prevent the MMRS from becoming stuck inside a thrombus; (2) new helix designs that produce an increased force to compensate for the weight added by the larger permanent magnet volume; (3) different head drill shape designs that have different interactions with thrombi. The two best MMRS designs were tested experimentally by removing a partially dried 1-hour-old thrombus with flow in a bifurcating artery model. The first MMRS disrupted a large portion of the thrombus. The second MMRS retrieved a small remaining piece of the thrombus. In addition, a tool for inserting, retrieving, and switching MMRSs during an experiment is presented and demonstrated. Finally, this paper shows that the two selected MMRS designs can perform accurate 3D path-following.more » « less
-
null (Ed.)Current designs of powered prosthetic limbs are limited by the nearly exclusive use of DC motor technology. Soft actuators promise new design freedom to create prosthetic limbs which more closely mimic intact neuromuscular systems and improve the capabilities of prosthetic users. This work evaluates the performance of a hydraulically amplified self-healing electrostatic (HASEL) soft actuator for use in a prosthetic hand. We compare a linearly-contracting HASEL actuator, termed a Peano-HASEL, to an existing actuator (DC motor) when driving a prosthetic finger like those utilized in multi-functional prosthetic hands. A kinematic model of the prosthetic finger is developed and validated, and is used to customize a prosthetic finger that is tuned to complement the force-strain characteristics of the Peano-HASEL actuators. An analytical model is used to inform the design of an improved Peano-HASEL actuator with the goal of increasing the fingertip pinch force of the prosthetic finger. When compared to a weight-matched DC motor actuator, the Peano-HASEL and custom finger is 10.6 times faster, has 11.1 times higher bandwidth, and consumes 8.7 times less electrical energy to grasp. It reaches 91% of the maximum range of motion of the original finger. However, the DC motor actuator produces 10 times the fingertip force at a relevant grip position. In this body of work, we present ways to further increase the force output of the Peano-HASEL driven prosthetic finger system, and discuss the significance of the unique properties of Peano-HASELs when applied to the field of upper-limb prosthetic design. This approach toward clinically-relevant actuator performance paired with a substantially different form-factor compared to DC motors presents new opportunities to advance the field of prosthetic limb design.more » « less
