Dielectric Electro Active Polymers (DEAP) has the potential of converting mechanical energy into useful electrical energy. This material consists of a silicone dielectric film material with a special corrugated surface and a very thin layer of metallic electrodes on both sides of the surface. As these materials allow large mechanical deformations with low operating forces, potential applications include using this material to convert the energy from the ocean waves, and wind. This work examined the capacitance to provide useful information in optimizing the electrical properties for specific applications, and to investigate how the electrical properties are affected by electrical and/or mechanical breakdown

Lovhoiden, Gunnar

Magbanua, James

Ng, Boon-Chai, Ph.D.

Rieger, Cody

English

Andrews University

Andrews UniversityDigital Commons @ Andrews UniversityPosters, Presentations, and Papers Undergraduate ResearchSummer 6-3-2015Microstructural Evaluation of DEAP Material afterStress RelaxationCody RiegerAndrews UniversityGunnar LovhoidenAndrews UniversityJames MagbanuaAndrews UniversityBoon-Chai Ng Ph.D.Andrews University, ngb@andrews.eduFollow this and additional works at: https://digitalcommons.andrews.edu/student-worksPart of the Computer Engineering CommonsThis Poster is brought to you for free and open access by the Undergraduate Research at Digital Commons @ Andrews University. It has been acceptedfor inclusion in Posters, Presentations, and Papers by an authorized administrator of Digital Commons @ Andrews University. For more information,please contact repository@andrews.edu.Recommended CitationRieger, Cody; Lovhoiden, Gunnar; Magbanua, James; and Ng, Boon-Chai Ph.D., "Microstructural Evaluation of DEAP Material afterStress Relaxation" (2015). Posters, Presentations, and Papers. 17.https://digitalcommons.andrews.edu/student-works/17Abstract	  	  Dielectric	   Electro	   Ac,ve	   Polymers	   (DEAP)	   has	   the	   poten,al	   of	  conver,ng	   mechanical	   energy	   into	   useful	   electrical	   energy.	   This	  material	   consists	   of	   a	   silicone	   dielectric	   film	  material	  with	   a	   special	  corrugated	   surface	   and	   a	   very	   thin	   layer	   of	   metallic	   electrodes	   on	  both	  sides	  of	   the	  surface.	  As	   these	  materials	  allow	   large	  mechanical	  deforma,ons	   with	   low	   opera,ng	   forces,	   poten,al	   applica,ons	  include	   using	   this	   material	   to	   convert	   the	   energy	   from	   the	   ocean	  waves,	   and	   wind.	   This	   work	   examined	   the	   capacitance	   to	   provide	  useful	   informa,on	   in	  op,mizing	   the	  electrical	  proper,es	   for	   specific	  applica,ons,	   and	   to	   inves,gate	   how	   the	   electrical	   proper,es	   are	  affected	  by	  electrical	  and/or	  mechanical	  breakdown.	  	  Introduc.on	  	  Dielectric	   electro-­‐ac,ve	   polymers	   are	   thin	   films	   made	   of	   a	   silicon	  material	   that	   offers	   a	   large	   amount	   of	   deforma,on.	   	   This	   silicon	  material	   is	   covered	   on	   both	   surfaces	   with	   metal	   electrodes.	   	   	   An	  applica,on	  of	  electrosta,c	  forces	  across	  the	  film	  thickness	  will	  cause	  film	   compression	   across	   the	   thickness,	   thus	   inducing	   in-­‐plane	  expansion.	   These	   characteris,c	   have	   poten,al	   applica,on	   as	  actuators	  and	  sensors.	  	  Experimental	  Procedure	  	  The	  DEAP	  sample,	  with	  gage	  length	  measuring	  8.3	  in	  and	  width	  0.6	  in	  width	  was	  cut	  in	  a	  way	  such	  that	  the	  stretching	  would	  be	  done	  in	  the	  compliance	  direc,on	  as	  shown	  in	  figure	  1.	  Both	  faces	  of	  the	  DEAP	  film	  were	   silver	   coated	   with	   silver	   electrodes	   spuNer	   coated	   to	   the	  silicone	   elastomer	   material.	   	   A	   secondary	   electron	   imaging	   of	   the	  silver	  electrodes	  on	  the	  silicone	  elastomer	  is	  shown	  in	  figure	  2.	  	  Strips	  of	  copper	  tape	  were	  placed	  across	  the	  width	  of	  the	  sample	  to	  allow	  the	  measurement	  of	  the	  capacitance	  using	  a	  HewleN	  Packard	  Model	  4284A	  Precision	  LCR	  Meter.	  	  	  	  	  	  	  	  	  	  	  	  Microstructural  Evalua.on  of  DEAP  Material  a5er  Stress  Relaxa.on  CyclesConclusion	  	  Samples	   of	   a	   80%	   strain	   DEAP	   material	   were	   subjected	   to	   15,000	  relax	   and	   stress	   cycles	   and	   their	   capacitance	  was	  measured	  both	  at	  the	  relax	  and	  the	  stress	  regions.	  	  Change	   in	   capacitance	   during	   the	   15,000	   cycles	   is	   about	   52%.	  	  Damaged or cracked coating continued to bridge to maintain conductive paths across the electrodes.  Acknowledgement  The	  DEAP	  was	  provided	  Danfoss	  PolyPower.	  This	  project	  is	  funded	  by	  the	  Andrews	  University	  Internal	  Faculty	  Research	  Grant.	  	  	  	  	  Cody	  Rieger,	  Gunnar	  Lovhoiden,	  James	  Magbanua	  and	  Boon-­‐Chai	  Ng	  Engineering	  and	  Computer	  Science,	  Andrews	  University	  TMS	  2015	  144th	  ANNUAL	  MEETING	  &	  EXHIBITION	  	  MARCH	  15-­‐19,	  2015	  •	  Orlando,	  FL,	  USA	  Figure	   1.	   	   Schema,c	   of	   the	   DEAP	   film	  with	   the	   metallic	   compliant	   electrodes	  deposited	  on	  both	   sides	  of	   the	  film.	  The	  material	   is	   been	   stretched	   along	   the	  compliance	   direc,on	   as	   shown	   in	   the	  diagram.	  Figure	  2.	  A	  low	  magnifica,on	  of	  the	  corrugated	  edge	  of	  the	  DEAP	  is	  shown	  on	  the	  le`	  and	  a	  higher	  magnifica,on	  (on	  the	  right)	  shows	  the	  silver	  coa,ng	  on	  the	  silicone	  elastomer	  film.	  Results	  and	  Discussion	  	  The	  DEAP	  sample	  was	  stretched	  to	  80%	  of	  its	  length	  and	  relaxed	  at	  a	  strain	   rate	   of	   7	   rev/min	   for	   a	   total	   of15,000	   cycles.	   	   A	   plot	   of	   the	  capacitance	   at	   relaxed	   and	   stressed	   level	   is	   shown	   in	   figure	   3.	   The	  capacitance	   increase	   as	   it	   stretched	   and	   on	   average	   there	   is	   an	  increase	  of	  around	  52%.	  This	  percentage	  increase	  is	  much	  larger	  than	  a	   previous	   experiment	   that	   stressed	   the	   samples	   to	   only	   25%	  with	  yield	   of	   only	   6%	   increase	   in	   the	   capacitance..	   	   Although	   the	   data	  showed	  a	  con,nuous	  overall	  decrease	  in	  the	  capacitance,	  it	  is	  normal	  and	   if	   the	   material	   is	   allow	   to	   sufficient	   ,me	   to	   recover,	   the	  capacitance	  measurement	  would	  increase.	   	  Nevertheless,	  the	  change	  in	  the	  capacitance	  had	  remained	  about	  constant.	  	  	  Figure	  3.	  A	  low	  magnifica,on	  of	  the	  corrugated	  edge	  of	  the	  DEAP	  is	  shown	  on	  the	  le`	  and	   a	   higher	   magnifica,on	   (on	   the	   right)	   shows	   the	   silver	   coa,ng	   on	   the	   silicone	  elastomer	  film.	  Image	  of	   the	  test	  sample,	  a`er	   the	  experiment,	   is	   shown	   in	  figure	  4.	  Note	  that	  a	  small	  piece	  of	   the	  coa,ng	  had	  ripped	  off	  from	  the	  edge.	  	  This	  might	  have	  been	  the	  result	  of	  residual	  chemicals	  le`	  behind	  a`er	  the	  ini,al	  removal	  of	  the	  coa,ng	  on	  the	  edge	  to	  prevent	  any	  shor,ng	  between	  the	  two	  surfaces.	   	  Other	  than	  that,	  the	  sample	   is	  s,ll	   intact	  and	   there	   are	   no	   other	   visible	   tears.	   Sample	   was	   cut	   into	   smaller	  pieces	  for	  observa,on	  under	  the	  scanning	  electron	  microscope.	  	  Figure	  4.	  A	  low	  magnifica,on	  of	  the	  sample	  showing	  the	  small	  tear.	   	  Sample	  is	  cut	  into	  small	  pieces	  for	  SEM	  imaging.	  Figures	   5-­‐9	   	   are	   secondary	   electron	   SE	   images	   of	   the	   highlighted	  sec,on	   shown	   in	   figure	   4.	   All	   the	   SE	   image	   showed	   varies	   stages	   of	  micro	   tears	   and	   micro	   fractures	   or	   peeling	   of	   the	   coa,ng	   from	   the	  silicone	   elastomer.	   In	   spite	   of	   the	   large	   numbers	   of	   creases	   in	   the	  silver	   coa,ng	   or	   breaks	   in	   the	   coa,ng	   and	   possibly	   in	   the	   spuNered	  electrodes	  observed	   in	   this	  material,	   there	  was	  no	  sudden	  change	   in	  the	   capacitance	   reading.	   These damaged or cracked coating continued to bridge to maintain conductive paths across the electrodes. 	  	  Figure	  5.	  SE	  images	  of	  sec,on	  A	  of	  the	  sample.	  	  Figure	  6.	  SE	  images	  of	  sec,on	  B	  of	  the	  sample.	  	  Figure	  7.	  SE	  images	  of	  sec,on	  C	  of	  the	  sample.	  	  Figure	  8.	  SE	  images	  of	  sec,on	  D	  of	  the	  sample.	  	  Figure	  9.	  SE	  images	  of	  sec,on	  E	  of	  the	  sample.	  	  

Microstructural Evaluation of DEAP Material after Stress Relaxation

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Microstructural Evaluation of DEAP Material after Stress Relaxation

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