E zcn nditions and sursaces 1 zb2 give zbn dif sur

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Unformatted text preview: n la i e n ti e no n tth r su e we, b b influence. Finally, we can define winrfluence. situations we can define winrfluence. situations we can define winrfluence. situations we can define worst-case situations for o st-case Finally, for o st-case Finally, for o st-case Finally, for different environmental conditions andferenftaces, irond enve conditions andferenftaces, irozbmenv.e, zcn .nditions andferenftaces, irozbmenv.e, zcn .nditions and surSaces, 1 , zb2 ,gi.v.e, zbn . dif sur env a nm gi tal : zb a n 2 . ( en)b a n 2 . : (: ) dif surSb env 1 , nd ,gi.tal b o dif surSb 10zv 1 , nd ,gi.tal b o f b 10zb and . Sb 10zb1 , zb2 , . . . , zbn . (: ) (10) suggestions for engineering solutionssuggvsaitong the etigtion ring solutionssuggvsaitong the etigtion ring solutionssuggvsaitong the etigtion ring solutions alleviating the stiction allee i t i ns for sn cinee allee i t i ns for sn cinee allee i t i ns for sn cinee Now we neprd bleeferin ceEMSht for both sureanepr,owlhiefh rwnceEMSht for both sureanee, whiefh rwnce height for both sureanee, whiefh rwnce height for both surfaces, which we e o a r ms enM heig . Now w f c ed b eme ineM heig . s a rcs e problems in MEMS. problems in MEMS. Now w f cesd a r c e e e Now w f c sd a r c e e e ag u n t hoos oT criptamean hoi gh i eu nnchoos e oT criptamean hei gh i eu nnchoos o s e ipt m of r ei gh ag n bc ag n t e s rt of r i g nt The starting point is a quantitative desheiptioning pounthis a qaiancitative tdebhetheioning pounthti,sgavqaiabyitative tdebhetheioning pounthti,sgavqaiabyitative tdebcrtheionean hought, giveain yhoose to be the mean height, given by T cr s art of r i g s e st rt of r ei g ag s surfaces in contact. We define a MEMS dein coinact. ich e define a MEMS n ein coinact. ich e define a MEMS n ein coinact. ich e define a MEMS device in which surfaces vice nt wh W d surfaces vice nt wh W surfaces vice nt wh W d n n n n n n 1 1 two surfaces a and b coming together arerfpossiblyand ne coming together 1arerfpossiblyand ne coming together 1arerfpossiblyand ne coming together 1are possibly prone 1 two su aces a pro b pro 1 1 aces pz zaN z ¯ z za.two su (zaN aand ro bb = 11) ¯ z¯. (zaN 11) za two su aces aand bb = ¯= ¯= N N zb ¯ zbza. = (zaN and zb = 11) ¯ zbN . (11) ¯ N to stiction. When we bring the surfaces cloner andenloser bring the surfaces cloner andenloser bring the b rfaces cloner andenloser bring the bzarf= n closer anandloser = n to stictios . Wh c we n n n n to stictios . Wh c we su to stictios . Wh c we su aces dc n n © N. Dechev, University of Victoria 24 N =1 N =1 N =1 N =1 = N =1 N =1 N =1 together, the first contact points will tyigedhpr, stieafilrstdcontoct points will tyigedhpr, stieafilrstdcontoct points will tyigedhpr, stieafilrstdcontoct points will yieldNpl1 stically due to o el t e la thc l y ue a o el t e la thc l y ue ta o el t e la thc l y ue a a or a givethe l are sforcese that it erea. can an wh ecalcuare sforcese that it erea. can an wh ecalculate thn se + z , we can giv n separatio e ¯ n sep ge o clo ¯ + ¯ , or giv the l late o ce ¯ + ¯ , n sep ge th lo p n the large force per unit area. Only when weargesforceseer unitharea.FOnly when weararation zaer uzbthawe FOnly ow en weararation zaer uzbthawe FOnly ow en we are so ce za thatbthe For anow ecalculate thn za + zb , we can now calculate the the l are o clo p that t e ¯ ¯ or giv n separatio lo ¯ pn force can be fully counteracted by thefmate rian ofetfullsurfounteras...
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This document was uploaded on 02/23/2014 for the course MECH 335 at University of Victoria.

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