Researchers at Peking University have developed a triboelectric energy harvesting generator that uses the human body -- instead of a grounded electrode -- as a conductor, offering a potential power source for wearables and low-power electronic devices. Based on the effects of contact electrification and electrostatic induction, the single-friction-surface triboelectric generator (STEG) can harvest the energy produced from a human hand or finger tapping and swiping a transparent panel made of the STEG material on the front surface of a mobile phone (see image below). According to the researchers, the generator achieved more than 200 mV output with a 4.7-µA/cm2 current density. For more details, see "Single-friction-surface triboelectric generator with human body conduit."
Energy harvesting mechanism and equivalent circuit of the (a) STEG with human body as an electrode; and (b) the STEG with grounded electrode when the finger taps the friction surface and shows a tendency to donate electrons.
(Image: Applied Physics Letters, 2014)
(See full-size image.)
Scientists at the Universitat Politècnica de València have developed silicon solar cells capable of absorbing IR radiation, offering the potential for creating more efficient silicon photovoltaic devices, which, until now, can only absorb and generate electricity from visible light. The researchers created PV cells on a micrometer-scale polycrystalline silicon sphere, which form resonators where IR light is effectively trapped until it's absorbed and converted into electricity (see image below). For more, see "All-silicon spherical-Mie-resonator photodiode with spectral response in the infrared region."
A scanning electron micrograph of a polysilicon microsphere cell depicted with the Mie modes of a classical spherical resonator overlaid.
(Image courtesy of Asociación RUVID)
In product news, NXP Semiconductors has announced power controllers designed to enable ultra-small 45 W adapters and power supplies. The TEA1836 ac/dc controller and TEA1892 synchronous rectification controller together form the Greenchip platform that can create an adapter with a standby power below 30 mW and casing temperature below 55° under full load conditions.
Fairchild Semiconductor announced an IGBT/MOSFET-drive optocoupler featuring the company's new Optoplanar packaging to achieve high insulation voltage and high noise immunity. The FOD8332 features a 1,414 Vpeak working insulation voltage and a minimum noise immunity of 35 kV/µs, VCM = 1,500 Vpeak.
Analog Devices has introduced a digital power controller with PMBus interface for high-density, isolated dc/dc power supply system applications. The ADP1055 features six PWM logic outputs that can be programmed using a GUI via the PMBus interface.
New mid-voltage MOSFETs from Texas Instruments are claimed to include the lowest on-resistance 80 and 100 V devices in TO-220 packages. The new NexFET MOSFETs include 14 devices that support input voltages from 40 to 100 V.
Power-One has expanded its open-frame ac/dc power supply portfolio to include products up to 450 W. The ABC450 series targets applications requiring high power rating with small size, while the MBC450 series targets medical applications.
Toshiba Electronics is offering a new series of 600-V high-speed switching-type super junction MOSFETs. Comprising the TK31N60X, TK39N60X, and TK62N60X, the DTMOS IV-H series features low on-resistance (from 0.088 to 0.040 Ω max at VGS = 10 V) and drain current ranging from 30.8 to 61.8 A.
Miniature high-side load switches from Micrel deliver up to 3 A. The MIC9416x family operates from 1.7 to 5.5 V and supports 1.5 V logic-level control and shutdown features in a six-ball WLCSP.
Advanced Power Electronics announced a small load switch with controlled turn-on and 22-mΩ on-resistance. The APE8937-HF-3 contains one N-channel MOSFET that can operate over an input voltage range of 0.8 to 5.5V and support a maximum continuous current of up to 4 A.
Diodes Inc. is offering what is claimed as the smallest 60-V N-channel power MOSFET with a sub-100-mΩ on-resistance. The DFN1616-packaged DMN6070SFCL has a footprint measuring 1.6 x 1.6 mm and a typical height of 0.5 mm and features a typical on-resistance of 74 mΩ at a VGS of 4 V.
Finally, Monolithic Power Systems has introduced a monolithic 900 V ac/dc switching regulator. Designed to minimize EMI for wireless communication in home and building automation applications, the MP110 features peak current mode control and programmable switching frequency to 300 kHz.