Increasing demand for low-power consumption in the electronics market combined with continued miniaturization of electronic components in analog or digital circuits has led to supply voltage being less than one volt for many devices. The supply voltage to integrated circuit (IC) devices are typically provided by AC-DC power converters, which convert high-frequency AC input voltage to a conditioned DC output voltage at a given power level. Low-voltage AC-DC converters generally consist of a diode rectifier, which is often composed of several conventional semiconductor diodes, an inductor, and capacitor. Rectifier diodes allow electrical current to flow in only one direction and are common in power supplies. They can handle higher current than regular diodes and are mainly used to change AC to DC.
Typical rectifier technology is bulky and has limited power-conversion efficiency. Also, conventional power conversion diodes have problems with thermal conductivity, heat generation, and manufacturing. To address these deficiencies, Army scientists and engineers have developed rectifier diodes incorporating single-wall carbon nanotube diodes.
The SWCNT diodes may be fabricated within an IC, electronics module, chip, or directly on a printed circuit board. They can also be configured as switching elements in circuits and electronic devices in which forward bias permits current to pass in an ON state and reverse bias does not enable current to pass in an OFF state.
Applications may include power supplies or power cords having power converters for computers, electronic devices, appliances or equipment, for example. In addition to these low-power device applications, the simple design and extremely small component size also allow for use in the traditional Complementary Metal Oxide Semiconductor (CMOS) field of low-voltage energy harvesting. This may be advantageous for devices such as radio frequency identification (RFID) chips, biomedical implants and devices, and wireless sensors that require the efficient conversion of an induced low-voltage AC signal into a useable DC output in a very small package.
- First use of carbon nanotubes for AC-to-DC power conversion
- A minimum number of components in the rectifier combined with a relatively easy fabrication process makes this a highly attractive technology for engineering AC-DC power converters for low-power micro- and nano-electronic devices
- Diodes may be configured for half-wave, full-wave, or full-wave bridge rectification
- Production of the SWCNT diodes is via CCVD
- US patent 9,018,734 available for license
- Potential for collaboration with Army researchers