A soft actuator inspired by the human bicep muscle could pave the way for soft-bodied robots that are safer and more dynamic than their rigid counterparts.
Developed by a team at the Wyss Institute at Harvard University, the shock-absorbing, soft actuators allegedly pose no danger to their environment, humans working alongside them, or the potential future robots equipped with them. The team said these soft actuators could lead to better assistive robots, for example, that could serve food, deliver goods and perform other tasks related to the service industry.
“Functionally, our actuator models the human bicep muscle,” said team leader George Whitesides, Ph.D., a Core Faculty member at Harvard’s Wyss Institute for Biologically Inspired Engineering and the Woodford L. and Ann A. Flowers University Professor of Chemistry and Chemical Biology in Harvard University’s Faculty of Arts and Sciences. “There are other soft actuators that have been developed, but this one is most similar to muscle in terms of response time and efficiency.”
The team said it took an unconventional approach to its design, relying on vacuum to decrease the actuator’s volume and cause it to buckle. We’ll let them explain:
“While conventional engineering would consider bucking to be a mechanical instability and a point of failure, in this case the team leveraged this instability to develop VAMPs (vacuum-actuated muscle-inspired pneumatic structures). Whereas previous soft actuators rely on pressurized systems that expand in volume, VAMPs mimic true muscle because they contract, which makes them an attractive candidate for use in confined spaces and for a variety of purposes.
VAMPs are modeled after the human bicep in terms of response time and efficiency. (Photo Credit: Wyss Institute at Harvard University)
“The actuator – comprising soft rubber or ‘elastomeric’ beams – is filled with small, hollow chambers of air like a honeycomb. By applying vacuum the chambers collapse and the entire actuator contracts, generating movement. The internal honeycomb structure can be custom tailored to enable linear, twisting, bending, or combinatorial motions.”
Although a complex control system has not yet been developed for VAMPs, the team said this type of actuation is easy to control due to its simplicity: when vacuum is applied, VAMPs will contract. They could be used as part of a tethered or untethered system, depending on environmental or performance needs.
Whitesides also said VAMPs are designed to prevent failure – even when damaged with a 2mm hole, the team showed that VAMPs will still function. In the event that major damage is caused to the system, it fails safely. Actuators powered by electricity or combustion could cause damage to humans or their surroundings, loss of vacuum pressure in VAMPs would simply render the actuator motionless.
“It can’t explode, so it’s intrinsically safe,” said Whitesides.
"Mfumo wa ""mwenye nguvu"" unaotokana na misuli ya biceps ya binadamu unaweza kuunda roboti zenye mwili laini, ambazo ni salama zaidi na zenye nguvu zaidi kuliko zile zenye nguvu." Vifaa hivyo vilivyotengenezwa na timu ya wataalamu wa Chuo Kikuu cha Harvard, vimepunguza mshtuko wa umeme na havina hatari kwa mazingira, wanadamu wanaofanya kazi pamoja nao, au roboti za wakati ujao. "Timu hiyo imesema ""vifungu hivi vya uendeshaji vya laini vinaweza kuongoza kwenye roboti bora za kusaidia, kwa mfano, ambazo zinaweza kuhudumia chakula, kutoa bidhaa na kufanya kazi zingine zinazohusiana na tasnia ya huduma.""" "Kutokana na utendaji wake, kifaa chetu cha kuendesha gari kinafanana na misuli ya biceps ya binadamu,"" alisema kiongozi wa timu George Whitesides, Ph.D., mwanachama wa Kitivo cha Chuo Kikuu cha Harvard katika Taasisi ya Wyss ya Uhandisi wa Kuchochewa na Biolojia na Woodford L. na Ann A. Flowers Chuo Kikuu Profesa wa Kemia na Kemia Biolojia katika Chuo Kikuu cha Harvard's Kitivo cha Sanaa na Sayansi. "Kuna actuators nyingine laini ambayo yamebuniwa, lakini hii moja ni sawa na misuli katika suala la muda wa majibu na ufanisi. ""Timu alisema alichukua mbinu ya kawaida kwa kubuni yake, kutegemea utupu kupunguza kiasi cha actuator na kusababisha buckle." "Wakati uhandisi wa kawaida ungefikiria bucking kuwa ukosefu wa utulivu wa mitambo na hatua ya kushindwa, katika kesi hii timu ilitumia ukosefu huu wa utulivu kuendeleza VAMPs (mfumo wa pneumatic ulioongozwa na misuli ya utulivu).""" Wakati waendeshaji laini wa zamani hutegemea mifumo ya shinikizo ambayo huongeza kiasi, VAMP huiga misuli ya kweli kwa sababu hufupisha, ambayo huwafanya kuwa mgombea wa kuvutia kwa matumizi katika nafasi ndogo na kwa madhumuni mbalimbali. VAMP ni mfano wa biceps ya binadamu katika suala la muda wa majibu na ufanisi. (Picha: Taasisi ya Wyss katika Chuo Kikuu cha Harvard) <unk>Mfumo wa kuendesha <unk> unaojumuisha mizunguko laini ya mpira au <unk>elastomeric<unk> <unk> umejaa vyumba vidogo vya hewa kama kiota cha asali. Kwa kutumia utupu vyumba kuanguka na mkataba mzima actuator, kuzalisha harakati. "Kama vile, ""kiungo cha ndani cha honeycomb kinaweza kuboreshwa ili kuwezesha mwendo wa linear, twisting, bending, au combinatorial."" - Ingawa mfumo tata wa kudhibiti haujaundwa kwa VAMPs, timu ilisema aina hii ya uendeshaji ni rahisi kudhibiti kwa sababu ya unyenyekevu wake: wakati utupu unatumiwa, VAMPs itashikamana." Wanaweza kutumika kama sehemu ya mfumo tethered au untethered, kulingana na mahitaji ya mazingira au utendaji. Whitesides pia alisema VAMP zimetengenezwa kuzuia kushindwa - hata wakati wa kuharibiwa na shimo la 2mm, timu ilionyesha kwamba VAMP bado itafanya kazi. Katika tukio kwamba uharibifu mkubwa ni kusababishwa kwa mfumo, ni kushindwa kwa usalama. Vifaa vya kuendesha vinavyoendeshwa na umeme au kuchoma vinaweza kusababisha uharibifu kwa wanadamu au mazingira yao, hasara ya shinikizo la utupu katika VAMP ingefanya tu kichocheo kisicho na mwendo. "Hawezi kulipuka, kwa hiyo ni salama", alisema Whitesides.