Related Experiment Video
Updated: May 10, 2025
16:01
An Experimental Protocol for Assessing the Performance of New Ultrasound Probes Based on CMUT Technology in Application to Brain Imaging
Published on: September 24, 2017
10.4K
Wireless ultrasonic power transfer using a pre-charged CMUT structure with a built-in charge storage capacitor
Muhammetgeldi Annayev1, Feysel Yalçın Yamaner2, Ömer Oralkan3
1Electrical and Computer Engineering, NC State University, 890 Oval, Drive, EB II, Raleigh, 27606, NC, USA. mannaye@ncsu.edu.
Microsystems & Nanoengineering
|April 22, 2025
Summary
This study introduces a novel pre-charged capacitive micromachined ultrasonic transducer (CMUT) for implantable medical devices (IMDs). The new design enables efficient wireless power transfer without DC bias, offering a significant advancement for medical technology.
Area of Science:
- Biomedical Engineering
- Materials Science
- Electrical Engineering
Background:
- Capacitive micromachined ultrasonic transducers (CMUTs) are promising for implantable medical devices (IMDs) due to their miniaturization and biocompatibility.
- Existing CMUTs often require a DC bias for power transfer, which is challenging for IMDs.
- Constant-charge mode operation in CMUTs eliminates the need for DC bias, making them more suitable for wireless power transfer in IMDs.
Purpose of the Study:
- To design and fabricate a novel pre-charged CMUT structure with an integrated charge storage capacitor.
- To demonstrate the feasibility of operating CMUTs in a constant-charge mode for ultrasound power transfer to IMDs.
- To evaluate the performance of the pre-charged CMUT in terms of charge retention, power reception, and efficiency.
Main Methods:
- Fabrication of a novel CMUT with a floating electrode for charge storage.
- Pre-charging the CMUT by applying DC bias while the floating electrode contacts the bottom electrode.
- Testing charge retention over two years and evaluating power reception and conversion efficiency under ultrasound stimulation.
- Demonstrating DC-bias-free operation for power reception in an IMD setting.
Main Results:
- The fabricated pre-charged CMUT successfully stored charges without leakage for approximately two years.
- The device operated effectively as a power receiver for IMDs without requiring a DC bias.
- Maximum received power of 10.1 mW (3.1 mW/mm²) was achieved with a 14.5% efficiency.
- Acoustic-to-electrical power conversion efficiency reached up to 29.7% at lower input power levels.
Conclusions:
- The novel pre-charged CMUT design is a viable solution for efficient wireless power transfer to IMDs.
- Eliminating the need for DC bias simplifies integration and enhances safety for implantable devices.
- This technology advances the development of self-powered and long-lasting IMDs.
More Related Videos
08:17Autonomous and Rechargeable Microneurostimulator Endoscopically Implantable into the Submucosa
Published on: September 27, 2018
8.4K
08:25Construction of a Wireless-Enabled Endoscopically Implantable Sensor for pH Monitoring with Zero-Bias Schottky Diode-based Receiver
Published on: August 27, 2021
2.4K
Related Concept Videos
01:26Energy Stored in a Capacitor: Problem Solving
1.0K
In 1749, Benjamin Franklin coined the word battery for a series of capacitors connected to store energy. Capacitors store electric potential energy that can be released over a short time. This property means capacitors have a wide range of applications.
Capacitor-discharge ignition is a type of ignition system commonly found in small engines where the energy released from a capacitor ignites an induction coil that, in turn, fires the spark plug.
To calculate the energy stored in a capacitor of...
Capacitor-discharge ignition is a type of ignition system commonly found in small engines where the energy released from a capacitor ignites an induction coil that, in turn, fires the spark plug.
To calculate the energy stored in a capacitor of...
1.0K
01:15Capacitors
380
Capacitors play a crucial role in car radios, where they filter and store frequencies to ensure clear signal reception. Essentially serving as energy storage devices, capacitors store energy within their electric field and are composed of two parallel conducting plates separated by a dielectric.
When a voltage source is connected to a capacitor, positive and negative charges accumulate on the opposite plates. This accumulation generates a potential difference that equals the product of the...
When a voltage source is connected to a capacitor, positive and negative charges accumulate on the opposite plates. This accumulation generates a potential difference that equals the product of the...
380
01:12Energy Stored in a Capacitor
3.5K
When an archer pulls the string in a bow, he saves the work done in the form of elastic potential energy. When he releases the string, the potential energy is released as kinetic energy of the arrow. A capacitor works on the same principle in which the work done is saved as electric potential energy. The potential energy (UC) could be calculated by measuring the work done (W) to charge the capacitor.
3.5K
01:20Design Example: Capacitance Multiplier Circuit
614
In integrated circuit technology, a capacitance multiplier is often utilized to produce a larger capacitance value when a small physical capacitance falls short. This is achieved by a circuit that multiplies capacitance values by a factor of up to 1000, such that a 10-pF capacitor can replicate the performance of a 100-nF capacitor.
The circuit illustrated in Figure 1 below incorporates two op-amps, with the first operating as a voltage follower and the second acting as an inverting amplifier.
The circuit illustrated in Figure 1 below incorporates two op-amps, with the first operating as a voltage follower and the second acting as an inverting amplifier.
614
01:25MOS Capacitor
625
A Metal-Oxide-Semiconductor (MOS) capacitor is a fundamental structure used extensively in semiconductor device technology, particularly in the fabrication of integrated circuits and MOSFETs (metal-oxide-semiconductor field-effect transistors). The MOS capacitor consists of three layers: a metal gate, a dielectric oxide, and a semiconductor substrate.
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
625
01:10Energy Stored in Capacitors
386
A parallel plate capacitor, when connected to a battery, develops a potential difference across its plates. This potential difference is key to the operation of the capacitor, as it determines how much electrical energy the capacitor can store.
By integrating the equation that relates voltage and current in a capacitor, one can derive an equation for the voltage across the capacitor at any given time. This equation is crucial in understanding and predicting the behavior of capacitors in...
By integrating the equation that relates voltage and current in a capacitor, one can derive an equation for the voltage across the capacitor at any given time. This equation is crucial in understanding and predicting the behavior of capacitors in...
386