DYNASUIT ARTIFICIAL MUSCLES TECHNOLOGIES AND DESIGNS FOR A COUNTERMEASURE BODY SUIT. ASTRA 2013, May 2013 ESTEC,The Netherlands 1 / 24

Transcription

1 DYNASUIT ARTIFICIAL MUSCLES TECHNOLOGIES AND DESIGNS FOR A COUNTERMEASURE BODY SUIT ASTRA 2013, May 2013 ESTEC,The Netherlands 1 / 24

2 Outline 1. Physilgical effects f weightlessness 2. Current cuntermeasures prgram and limitatins 3. DYNASUIT prject bjectives 4. Scenaris and technlgy selectin 5. EAP stack actuatrs demnstratr 6. Sigma pneumatic demnstratr 7. Cnclusins ASTRA 2013, May 2013 ESTEC,The Netherlands 2 / 24

3 Main Physilgical Effects During and After Lng Duratin Missins Reductin f muscle mass and strength (mainly lwer limbs) Reductin f bne density (risks f fracture, increased cnvalescence) Spine elngatin (back pain, EVA suit cnfiguratin) Reductin f aerbic capacity (increased HR, reduced exercise/wrk capacity) Orthstatic intlerance (bld pressure cntrl, risks f syncpe during re-entry) Neurvestibular decnditining (balance and gait cntrl detriment when returning) ASTRA 2013, May 2013 ESTEC,The Netherlands 3 / 24

4 Why Implement Cuntermeasures? T cunteract the physilgical effect f micrgravity T supprt EVA (bth fr perfrmance factrs and preventin f DCS) T retain Earth physical standards in the event f emergency T retain Earth physical standards t reduce health risks n return t Earth and time f cnvalescence ASTRA 2013, May 2013 ESTEC,The Netherlands 4 / 24

5 Stimulatin Requirements Bnes Mechanical lading (static r dynamic) that mimics Earth-like gravity, via weight bearing stress and/r during muscular cntractins, (nt 24h/day) Ptential benefits f lw level vibratin stimulus / impulses Muscles Small number f high intensity muscular cntractin fr mbiliser muscles Repetitive sustain lw intensity muscular cntractin fr stabiliser muscles Spine elngatin Nrmal static cmpressin and lw intensity mbility exercises Sensrimtr Mechanical stimulatin n the sle fr prpriceptive stimulatin Optimal stimulatins are still under investigatin ASTRA 2013, May 2013 ESTEC,The Netherlands 5 / 24

6 In-Flight Cuntermeasures Devices and Methds Cardivascular, Muscles (Treadmill and Cyclmeter) Muscle Grwth (IRED, ARED, FlyWheel) Bne Grwth (Pinqvin, skynsuit) ASTRA 2013, May 2013 ESTEC,The Netherlands 6 / 24

7 Current Cuntermeasures: Main Limitatins Physilgical effects decnditinning still ccurs after lng duratin flights Crew time cnsuming (activities, maintenance) Large size, mass and pwer usage Vibratin islatin required Nt easily individually tailred Can invlve pain and discmfrt, such as treadmill harness systems ASTRA 2013, May 2013 ESTEC,The Netherlands 7 / 24

8 DYNASUIT Prject Main Objective Design f a new intravehicular bdy suit fr daily cuntermeasure stimulatin, including state f the art technlgies in artificial muscles actuatin, bdy mnitring and bifeedback The main bjectives f the prject are summarized in the three fllwing statements: T define the needs and requirements fr, t develp cncepts and prpse a detailed design f DYNASUIT, an intelligent bifeedback suit which includes artificial muscles fr cuntermeasures purpses, with the aim f imprving crew health. T build demnstratrs fr the tw mst prmising technlgies f artificial muscles, in rder t validate their cncepts and designs. T frmulate recmmendatins fr the future DYNASUIT implementatin and fr additinal bifeedback user scenaris and applicatins. ASTRA 2013, May 2013 ESTEC,The Netherlands 8 / 24

9 Scenaris and Technlgies Selectin First analysis f relevant cuntermeasure scenaris and preliminary cncepts f artificial muscles technlgies have been perfrmed in a first phase f the study Tw mst prmising assciatins f scenaris and technlgies selected fr detailed cncepts and demnstratrs Design, building and testing f tw artificial muscles demnstratrs with the purpse t demnstrate their feasibility fr integratin in a cuntermeasure suit ASTRA 2013, May 2013 ESTEC,The Netherlands 9 / 24

10 Scenari 1: Mechanical stimulatin f the ft sle Purpse: Lwer leg stabilizer muscles and bnes stimulatin, neurmtr decnditining Cncept: Array f EAP stack actuatrs t prduce time and space varying pressure n the ft sle Similar technlgy applicable fr bdy suit vibratin in superpsitin t a gravity lading, with distributed EAP stack actuatrs alng the z-axis ASTRA 2013, May 2013 ESTEC,The Netherlands 10 / 24

11 Scenari 2: +Gz bdy vertical cmpressin Purpse: Stimulatin f the bdy bne structure thrugh a cntinuus lng axis lading, graded as a replicatin f the +Gz prfile experienced n Earth. Reductin r preventin f atrphy f stabilizer and mbilizer muscles and bne, spine elngatin and back pain Cncept: Sigma actuatrs integrated in series in the fabric, pressurized by a manual r electrical pump σ-actuatr ASTRA 2013, May 2013 ESTEC,The Netherlands 11 / 24

12 EAP Stack Demnstratr : EAP Principle Large number f stacked thin silicne film pieces (ca. 80μm) which are cated with cmpliant electrdes IR Radiatin Interlaminar Crsslink Pltted Electrde Silicne Layers Supprt ASTRA 2013, May 2013 ESTEC,The Netherlands 12 / 24

13 EAP Stack Demnstratr : Descriptin Characteristics: Max. edge length f the crss-sectin: 14mm Effective length f the tested actuatr: 23.8mm Thickness f each dielectric layer: 47.6um Number f layers: 500 Actuatin Vltage: < 2 kv Pillar Switching time 5ms Max. required cntractin: >1mm Min. required defrmatin under external lad: 3% Laser displacement measurement Pillar Frce intrductin plate Vias Circuit bard tracks Spring Hrizntal sliding bar - Supprting plate Electrical cntact Actuatr Frce intrductin plate ASTRA 2013, May 2013 ESTEC,The Netherlands 13 / 24

14 Stress (MPa) EAP Stack Demnstratr: Experiments and Results (1) Experiment 1: Determinatin f the passive mdulus 0,10 Cmpressin mdulus = 0,6 MPa 0,08 0,06 Cmpressin mdulus = 1 MPa 0,04 0,02 Cmpressive test realized with Zwick Z010 Cntractin speed = 1mm/min 0,00 0,00 0,05 0,10 0,15 Cntractin (-) Between 0.6 and 1 Mpa, depending n the stress dmain Stiffening effect f the electrde material ASTRA 2013, May 2013 ESTEC,The Netherlands 14 / 24

15 Cntractin [-] EAP Stack Demnstratr: Experiments and Results (2) Experiment 2: Measurement f the static electr-mechanical prperty < 0.1 Hz, between 0 and 2kV Testserie 3 Apprach Field [V/um] Maximum applied field: 40V/um Maximum achieved cntractin: 3% Applicatin requirement: 6% f cntractin, crrespnding t V/um ASTRA 2013, May 2013 ESTEC,The Netherlands 15 / 24

16 Mtin [mm] EAP Stack Demnstratr: Experiments and Results (3) Experiment 3: Measurement f the dynamic electr-mechanical prperty Between 0 and 100 Hz Square and sinusidal vltage slicitatin Pulse 1000V Sinus+ 1000V Sinus V Pulse 1500V Sinus+ 1500V Sinus V Frequency [Hz] Amplitude f cntractin decreases with increasing frequency (material viscsity, electrde resistance, current limitatin f the pwer supply) Pulse activatin creates higher amplitude than sinusidal activatin ASTRA 2013, May 2013 ESTEC,The Netherlands 16 / 24

17 avarage el. Pwer [W] EAP Stack Demnstratr: Experiments and Results (4) Pwer cnsumptin Between 0 and 100 Hz Square and sinusidal vltage slicitatin 10 1 Pulse 1000V Sinus+ 1000V Sinus V Pulse 1500V Sinus+ 1500V Sinus V Frequency [Hz] Pwer cnsumptin is increasing by increasing activatin frequency If 30W (requirement) is limit and with 50 actuatrs: 10Hz actuatin frequency is the limit Need ptimisatin with peratin in phase shifted mde ASTRA 2013, May 2013 ESTEC,The Netherlands 17 / 24

18 Sigma Pneumatic Actuatr: Principle An airtight bladder, made f a thin fil is placed in a pcket, inserted in the suit between tw fabric layers. Upn inflatin, the thickness f the bladder increases pressing n the ambient fabric which results in a cntractive frce. ASTRA 2013, May 2013 ESTEC,The Netherlands 18 / 24

19 Sigma Pneumatic Actuatr: Descriptin Gals: Demnstrate the functin f the sigma actuatrs Demnstrate the integratin f the sigma actuatrs in a suit Demnstrate the generated frce as a functin f the air pressure Characteristics: Upper bdy stimulatin Six Sigma actuatrs in series n the frnt and n the back Independent pressurizatin, thrugh electrical pump SPV6T Fabric frm plyamide (Scheller textiles), bladder frm thin PU-fil ASTRA 2013, May 2013 ESTEC,The Netherlands 19 / 24

20 Sigma Pneumatic Actuatr: Experiments and Results (1) Experiment 1: Passive frce deflectin charcateristic Different weights attached at the bttm f the suit under activatin Nn-linear characteristic The current fabric is nt stiff enugh ASTRA 2013, May 2013 ESTEC,The Netherlands 20 / 24

21 Sigma Pneumatic Actuatr: Experiments and Results (2) Experiment 2: Vertical Frce and skin pressure Installed n an instrumented manikin The frce increases strngly fr lw pressure values and levels ff at higher pressure values at a level arund 45kg The maximal skin pressure is abut 55 mmhg (abve requirement f 40 mmhg, mitigatins) ASTRA 2013, May 2013 ESTEC,The Netherlands 21 / 24

22 Sigma Pneumatic Actuatr: Experiments and Results (3) Experiment 3: Tests n Human Subjects Activatin at a medium pressure f 500 mbar 60 s t dn, 30 s t dn-ff Cmpressin frce well perceptible between the shulder and the hip Bending trs frward, backward and sideward nt restricted Stiff feeling in the circumference. This culd be imprved by dividing the actuatrs in tw r three chambers in the circumference Sweat when wearing the suit fr lnger perid Fr female subjects the suit needs t be carefully designed at the breast regin High discmfrt at the crtch regin due t the the way the suit is fixed ASTRA 2013, May 2013 ESTEC,The Netherlands 22 / 24

23 Cnclusins EAP: Feasibility f the EAP stack actuatr t prvide vibratin stimulatin, althugh higher defrmatin wuld be needed New techniques f manufacturing fr silicne based actuatrs culd imprve the achievable defrmatin until 10% in a shrt/medium time frame (+/- 1 year) Further tests shall be perfrmed with a full integratin f several actuatrs with feeding lines and energy transfer between the stacks, as well as tests with human fr validatin Pneumatic: The feasibility t prvide axial lading has been clearly demnstrated The lad intrductin t the bdy, the stiffness f the material, the shape and numbers f sigma actuatrs have t be ptimized t imprve the cmfrt and the usability f the suit. The cncept shall have t be extended t the lwer part (legs), where the decnditining is very imprtant. ASTRA 2013, May 2013 ESTEC,The Netherlands 23 / 24

24 Acknwledgment Funding Onging activity, funded by ESA in the framewrk f the General Studies Prgramme (GSP) Partners ASTRA 2013, May 2013 ESTEC,The Netherlands 24 / 24