Batterija ġdida impjantabbli għal apparati li jaħdmu mill-bniedem?
Skont rapporti tal-midja barranija, ix-xjentisti bħalissa qed jistudjaw il-konverżjoni ta 'enerġija mekkanika, termali u kimika fil-ġisem tal-bniedem f'enerġija elettrika permezz ta' effetti pjeżoelettriċi, konverżjoni ta 'enerġija termali, effetti elettrostatiċi, u reazzjonijiet kimiċi, sabiex jipprovdu apparat li jintlibes jew impjantabbli. . mħaddem minn.
In ISing the Body Electric, poet Walt Whitman speaks fondly of the "action and power" of "beautiful, strange, breathing, laughing muscles." More than 150 years later, MIT materials scientist and engineer Canan Dagdeviren and her colleagues are using research to give new meaning to Whitman's poetry. They are working on a device that can generate electricity from the beating of people's hearts.
Today's electronics are so powerful that the computing power of smartphones far exceeds the processing power of NASA's associated crew equipment when the first astronauts were sent to the moon in 1969. Over time, the rapid development of technology has led to higher and higher expectations for wearable or implantable devices.
The main drawback of most wearable and implantable devices is still battery life, whose limited battery capacity can limit the long-term use of the device. When the pacemaker's power runs out, all you need to do is replace the battery for the patient's surgery. The fundamental solution to this problem may lie within the human body, which is rich in chemical, thermal, and mechanical energy. This has led scientists to repeatedly study how the device harvests energy from the human body.
For example, the movement a person makes while breathing can generate 0.83 watts of energy; the human body has about 4.8 watts of heat in a calm state; and a person's arms can generate up to 60 watts of energy when exercising. A pacemaker needs only five millionths of a watt to run for seven years, a hearing aid needs only one thousandth of a watt to run for five days, and a watt of power can power a smartphone for five Hour.
Issa Dagviren u l-kollegi qed jinvestigaw kif jużaw il-ġisem tal-bniedem innifsu bħala sors ta 'enerġija għall-apparat. Ir-riċerkaturi diġà bdew jittestjaw l-apparat li jintlibes jew impjantabbli fl-annimali u l-bnedmin.
Waħda minn dawn l-istrateġiji tal-ħsad tal-enerġija tinvolvi l-konverżjoni tal-enerġija mill-vibrazzjoni, pressjoni u stress mekkaniku ieħor f'enerġija elettrika. Dan il-metodu jipproduċi l-hekk-pjeżoelettrika, li tintuża komunement fil-kelliema u l-mikrofoni.
A commonly used piezoelectric material is lead titanate zirconate, but its high lead content has raised concerns because lead is too toxic to humans. "But to break down the lead structurally, you need to heat it to more than 700 degrees Celsius," Dagvilen said. "You'll never get to that temperature in the human body."
To take advantage of the piezoelectric effect, Dagviren and her colleagues developed flat devices that can be attached to organs and muscles such as the heart, lungs and diaphragm. These devices are "mechanically invisible" because their mechanical properties are more similar to their environment, so they move without interfering with the normal functioning of these tissues.
So far, the devices have been tested on cows, sheep and pigs, because these animals have hearts about the same size as a human heart. "When these devices are mechanically distorted, they generate positive and negative charges, voltages and currents, so that energy can be harvested to charge the battery," Dagviren explained. "You can use them to run the heart biomedical devices such as pacemakers, rather than having to be surgically replaced every six or seven years after the battery is depleted."
Ix-xjentisti qed jiżviluppaw ukoll ħsad tal-enerġija pjeżoelettriċi li jintlibsu li jistgħu jintlibsu fuq l-irkoppa jew il-minkeb, jew imqiegħda fiż-żraben, qliezet jew ħwejjeġ ta 'taħt. B'dan il-mod, persuna tista 'tiġġenera l-elettriku għall-elettronika meta timxi jew titgħawweġ.
It may seem counterintuitive when designing piezoelectric components that you don't need the best materials for generating electricity. For example, instead of choosing a material that can convert 5 percent of mechanical energy into electrical energy, scientists may use materials that have a conversion efficiency of 2 percent or less. If it translates more, "it may do so by putting more load on the body, but the user certainly doesn't want to get tired from that," Dagvilen said.
Another energy harvesting method is to use thermoelectric conversion materials to convert bulk heat into electrical energy. "Your heart beats more than 40 million times a year," Dagviren points out. All of this energy is dissipated as body heat—a potential resource that can be captured.
Human thermal power generation does face some major problems. This type of energy conversion often relies on temperature differences, but the body's body temperature often remains fairly constant, so the temperature differences within the body are not high enough to generate a lot of electricity. However, if these devices could be exposed to a relatively cool external environment while collecting body temperature, the problem could be solved.
Scientists are exploring heat-generating devices for wearable devices, such as powering watches. The heat produced by the human body could, in principle, generate enough electricity to power wireless health monitors, artificial hearing aids and cerebral cortical stimulators for Parkinson's disease.
Barra minn hekk, ix-xjentisti qed jippruvaw ukoll iħaddmu apparati permezz tal-effett elettrostatiku komuni. Meta żewġ materjali differenti jaħbtu jew togħrok kontra xulxin ripetutament, il-wiċċ ta 'wieħed jista' jaqbad elettroni mill-wiċċ ta 'l-ieħor, jakkumula ċarġ elettriku, fenomenu magħruf bħala elettrifikazzjoni triboelettrika. Vantaġġ ewlieni tal-elettrifikazzjoni triboelettrika huwa l-abbiltà ta 'kważi l-materjali kollha, kemm naturali kif ukoll sintetiċi, li jiġġeneraw elettriku statiku, li tiftaħ ħafna possibbiltajiet għar-riċerkaturi biex jiddisinjaw varjetà wiesgħa ta' aġġeġġi.
"The more I study triboelectricity, the more exciting it is, and the more applications it may have," said Georgia Tech nanotechnology expert ZhongLin Wang, co-author of the paper. "I can Seeing myself committing to this research for the next 20 years."
The amount of electricity produced by different materials through triboelectricity varies widely, so scientists are experimenting with a variety of materials. The researchers made grids of cubes that resemble microscopic city blocks, nanowires that resemble bamboo forests, and pyramid arrays of the kind that resemble the Great Pyramid of Giza. Not only do these materials "look beautiful," Wang said, but covering the surface with an array of pyramids can increase power generation by a factor of five compared to flat panels.
Researchers have conducted experiments in mice, rabbits and pigs, where they have tested pacemakers, heart monitors and other implantable devices powered by breathing and the rapid heartbeat. "We're also investigating whether we can use triboelectricity to stimulate cell growth and accelerate wound healing," Wang said. "Also, we've started triboelectric experiments on neural stimulation to see if we can do it for neuroscience. any contribution."
Wang and his colleagues also designed wearable devices that are triboelectrically charged. For example, they made triboelectric cloths that can charge flexible wristbands with lithium-ion batteries. The gadget powers a Bluetooth-enabled wearable heart rate monitor, which transmits its data wirelessly to a smartphone. "The mechanical energy generated by human movement every day can be converted into electricity through our cloth," Wang said.
Strateġija oħra tiddependi fuq apparati msejħa ċelloli tal-bijofjuwil, li jiġġeneraw l-elettriku permezz ta' reazzjonijiet kimiċi bejn l-enzimi u l-{0}}molekuli tal-ħażna tal-enerġija fil-ġisem, bħall-glukożju fid-demm, jew il-laktat imnixxi fl-għaraq. Pereżempju, cellobiose dehydrogenase estratt mill-fungi jista 'jkisser il-glukożju u jiġġenera kurrenti elettriċi f'tubi tal-karbonju nanometru (billjunth ta' metru).
L-għażla ta 'l-enzimi tista' tkun delikata. Pereżempju, filwaqt li bosta xjentisti sabu li l-glukożju oxidase jista 'jiġġenera l-elettriku fiċ-ċelloli tal-bijofjuwil impjantati fil-ġrieden tal-laboratorju, l-enzima tipproduċi wkoll perossidu tal-idroġenu (komponent komuni tal-bliċ), li jista' tiddeterjora l-prestazzjoni tal-apparat u tikkawża ħsara lill-ġisem.
Fi studju ieħor, mikrografi ta 'l-elettroni ta' l-iskannjar urew li n-nanotubi tal-karbonju użati f'ċellula sperimentali tal-bijofjuwil kienu kapaċi jiġġeneraw l-elettriku mill-ġisem. It-tubi huma miksija b'enzimi li jipproċessaw molekuli ta 'enerġija naturali, bħal lactate fl-għaraq jew glukożju fid-demm. L-għodda hija elettroattiva filwaqt li tipprovdi erja tas-superfiċje kbira għall-enzimi biex jirreaġixxu mal-enerġija, li tippermetti li jiġi ġġenerat aktar elettriku għal volum partikolari.
Ix-xjentisti Franċiżi ħolqu wkoll ċellula tal-bijofjuwil ibbażata fuq nanotubi tal-karbonju miksijin b'enżima-li għandha daqs ta' madwar nofs kuċċarina u, meta tiġi impjantata fil-ġrieden, tista' tiġġenera biżżejjed elettriku biex tħaddem termometru LED jew diġitali billi jirreaġixxi maz-zokkor fid-demm. . L-esperimenti wrew ukoll li ċ-ċelloli tal-bijofjuwil tad-drapp minsuġa f'faxex tar-ras u polz jistgħu jiġġeneraw biżżejjed elettriku biex iħaddmu l-arloġġi permezz tar-reazzjoni kimika tal-aċidu lattiku fil-ħalib u l-għaraq b'enzimi.
Safejn Dagvilen jaf, l-ebda wieħed minn dawn l-apparati bħalissa mhu fis-suq. Iżda hija tbassar li t-teknoloġija se tkun fis-suq f'inqas minn għaxar snin. Fil-futur, l-apparati tal-ħsad tal-enerġija jistgħu jsiru aktar adattati għall-ġisem tal-bniedem. Dagvilen u l-kollegi tagħha saħansitra qed jaħdmu fuq aġġeġġi li jiġġeneraw enerġija degradabbli-.
"Imagine," she said, "putting a device in your body, and after a while it degrades into molecules that dissolve into body fluids, and you can take it out without opening your chest: we can use biodegradable Materials such as silk and zinc oxide that decompose over time."
