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Self-bal­anc­ing elec­tric uni­cy­cle

MIT stu­dent Stephan Boyer has cre­ated a self-bal­anc­ing elec­tric uni­cy­cle. Called Bul­let, the cy­cle packs a cus­tom Mig-welded steel chas­sis, two 7Ah 12V bat­ter­ies, an At­mega328p mi­cro­con­troller chip and a 450-watt elec­tric mo­tor. It leans for­ward to ac­cel­er­ate and leans back to brake. The top speed is about 24 kilo­me­tres per hour, and the cy­cle eas­ily trav­els eight kilo­me­tres on a sin­gle charge.

Bul­let in­te­grates read­ings from the gyro and ac­celerom­e­ter us­ing a com­ple­men­tary fil­ter. To bal­ance, the an­gle es­ti­mate is fed through a pro­por­tional-in­te­gral-deriva­tive loop ( with no in­te­gral term). The loop runs at 625 Hz. The out­put from this stage de­ter­mines the duty cy­cle of a 1.22khz pulse-width mod­u­la­tion sig­nal, which is con­nected to the Hbridge. The code is writ­ten in ‘C’.

Charge your cell­phone with water

Swedish com­pany MYFC has de­vel­oped a power source that con­verts hy­dro­gen into electricity to charge mo­bile de­vices.

Pow­ertrekk uses plain tap water to charge mo­bile de­vices. It is pocket-size, light­weight and fuel-cell-driven. Made from foils and ad­he­sives, Fuel­cel­lStick­ers form a flex­i­ble assem­bly less than 2.75mm thick. Since the hy­dro­gen fuel can be sup­plied from sev­eral al­ter­na­tive sources, the sys­tem is ‘flex­i­fuel.’

The fuel cell in­side Pow­ertrekk is a com­pletely pas­sive sys­tem. With­out fans or pumps, it silently con­verts hy­dro­gen into electricity via its pro­ton ex­change mem­brane. The chem­istry process is safe, con­trol­lable and ecofriendly, and the only byprod­uct from the fuel cell is a lit­tle water vapour. To op­er­ate, hy­dro­gen must be sup­plied to the fuel cell, and the fuel cell ex­posed to the open air.

Liq­uid key­board for touch­screen tablets

Typ­ing on a tablet’s touch­screen was never this easy. Thanks to ‘Liq­uidKey­board’ tech­nol­ogy de­vel­oped by com­puter sys­tems re­searcher Chris­tian Sax along with his col­league Hannes Lau at the Univer­sity of Tech­nol­ogy in Syd­ney, a key­board can morph around the user’s fin­gers to type on the tablet’s touch­screen us­ing both hands.

The tech­nol­ogy fol­lows the tra­di­tional QWERTY key­board sys­tem. A vir­tual key­board is de­vel­oped with the Liq­uidkey­board soft­ware, which adapts au­to­mat­i­cally to the user’s hand phys­i­ol­ogy, such as hand size and fin­ger po­si­tion. As soon as the first four fin­gers touch the sur­face—in one fluid mo­tion—an en­tire key­board is con­structed. The sys­tem senses the pres­sure and po­si­tion of the user’s fin­gers on the touch­screen.

Liq­uid key­board for tablets

Power Trekk uses plain tap water to charge mo­bile de­vices

Bul­let goes 8 km on a sin­gle charge

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