researches for the decrease of the frictions in mechatronic

Universitatea Tehnica“Gheorghe Asachi” din Iasi

RESEARCHES FOR THE DECREASE OF THE FRICTIONS INMECHATRONIC MICROSYSTEMS

GRANT IDEI: ID_607 Contract 381/20072007 - 2010

Director of the grant: Prof. Dr. Ing. Dumitru N.Olaru

Members:Conf. Dr. Ing. Gheorghe PrisacaruSl. Dr. Ing. Gelu IanusIng. Ciprian Stamate – DoctorandIng. Puiu George Constantin - Doctorand

CERCETARI PRIVIND REDUCEREA FRECARII IN MICROSISTEME MECATRONICEIDEI ID_607, CONTRACT 381/2007 Director: prof. dr. ing. Dumitru Olaru

Universitatea Tehnica“Gheorghe Asachi” din Iasi CERCETARI PRIVIND REDUCEREA FRECARII IN MICROSISTEME MECATRONICE

IDEI ID_607, CONTRACT 381/2007 Director: prof. dr. ing. Dumitru Olaru

MEMS – class I- Fixed elements

MEMS – class II- Mobile elements without contacts and friction

MEMS- class III – With mobile elements and sticktion phenomena

MEMS – class IV – With mobile elements having direct contacts with friction, adherence. and wear (microtribology problems): micromotors, microgears, microturbines, microguides, etc.



The diminution of friction in microsystems has beneficial effects, at least on the following directions:

1. The lowest consume of energy and thus the usage of some autonomous energy microsources with dimensions as little as possible (microbatteries);

2.The avoidance of blocking at micro interaction level;

3.The decreasing of stick-slip phenomena with the growing work precision in microsystems.



OBJECTIVES

Objectiv nr.1 Design of the experimental researches to determine the limits of dimensions for adherence and capillaryeffects. Objectiv nr.2Acquisition of the equipments, softs, materials.

2007

2008Objectiv 1. Acquisition of the equipments.Objectiv 2. Experimental researches to determine the limits of dimensions for adherence and capillary effects.

Objectiv 3. Elaboration of the complex analytical models to evaluate the friction forces and moments in sliding and rolling microtribosystems

Objectiv 1. Development of the new analytical models for study of the friction processes in the microsystems with microrolling tribosystems ( microbearings, microguides). Objectiv 2. Aquisition of the materials, equipments, soft. Objectiv 3. Experimental validation of the models

.Objectiv 1. New solution to reduce the friction in microsystems based on the rolling friction.2010

. Objectiv 2. Experimental validations.Objectiv 3. Realisation of the book: FRICTION IN THE MICROSYSTEMS

2009



Most important acquisitions

Termo-Higro-Barometer COMETER, model D4141 and accessories, softRecord of the temperature, pressure and humidity with connection on PC by USB;

MICROTRIBOMETER CETR - UMT 2M and accessories, soft

Pin on disc friction and wear tests with 3 bidirectional forces sensors:- 0,1- 10mN, with sensibility of 1μN;

- 5 - 500mN, with sensibility of 50μN;

- 0,2 - 10N, with sensibility of 1mN

Computer, scanner, soft, printer, silicon wafers, materials.



CONFERENCES2007

International Conference on Tribology ROTRIB’07 Bucuresti, www.rotrib.pub.roD.N. Olaru, Gh. Prisăcaru, P. Lorenz, Friction in linear rolling systems for microactuators, RO-084, Proc. of 10th International Conference on Tribology, ROTRIB’07, Nov. 8-10, Bucharest, 2007, Ed. Politehnica Press, ISBN 978-973-78-38-49-0;C. Stamate, D.N. Olaru , Experimental determinations of a water meniscus between a steel ball and a glace surface, RO-078, Proc.of 10th International Conference on Tribology, ROTRIB’07, Nov. 8-10, Bucharest, 2007, Ed. Politehnica Press, ISBN 978-973-78-38-49-0;G. Ianus, D.N. Olaru, P. Lorenz , Adhesion in the microsystems, RO-096, Proc. of 10th International Conference on Tribology,ROTRIB’07, Nov. 8-10, Bucharest, 2007, Ed. Politehnica Press, ISBN 978-973-78-38-49-0;G.V. Puiu, D.N. Olaru,V. Puiu Friction torque and efficiency in ball – screw systems, RO-083, Proc. of 10th International Conference on Tribology, ROTRIB’07, Nov. 8-10, Bucharest, 2007, Ed. Politehnica Press, ISBN 978-973-78-38-49-0;

2008

16 th International Colloquium Tribology, Esslingen,Germany, www.tae.deD.N.Olaru, C.Stamate, Gh. Prisacaru, P.Lorenz, The Influence of the Atmospheric Condensed Water on Friction in a Micro Rolling Systems, Proc. of 16th International Colloquium Tribology, January 15-17,2008,T.A.Esslingen,Germany, Session B6.

53th International Colloquium IWK, TU Ilmenau, Germany, www.tu-ilmenau.de/uni/index.php?id=6550D.N. Olaru, C. Stamate, Gh. Prisacaru, P. Lorenz: The Influence of the Atmospheric Condensed Water on Friction in Micro Systems, 53th International Colloquium IWK, TU Ilmenau, 8-12 September, 2008;

14th International Conference on EHD Lubrication and Traction, VAREHD´14, Suceava, www.varehd.usv.roC. Stamate, D. Olaru: A new pin disc microtribometer, International 14th Conference on EHD Lubrication and Traction, VAREHD´14, 10-11 October 2008, Suceava, Romania, ISSN: 1844-8917.

D. Olaru, C. Stamate: Rolling friction in the mechatronic microsystems, International 14th Conference on EHD Lubrication and Traction, VAREHD´14, 10-11 October 2008, Suceava, Romania, ISSN: 1844-8917;

International Conference WESIC’08, Bucuresti, www.incdmtm.ro/docs/conferinta/35. Rolling Friction in the MechatronicMicrosystems.pdf

C. Stamate, D. Olaru, Gh. Prisacaru, Gelu Ianus: Rolling Friction in the Mechatronic Microsystems, International Conference „6th WORKSHOP ON EUROPEAN SCIENTIFIC AND INDUSTRIAL COLLABORATION ON PROMOTING ADVANCED TECHNOLOGIES IN MANUFACTURING” –WESIC’08, 25-26 September 2008, Bucharest, Romania, pp.295-302, ISSN: 1584-5982;



CONFERENCES

3rd Vienna International Conference on Nano-Technology www.oetg.at/viennano09/html/postersession.html

2009

2nd International Conference ADEMS’09, 24-25 Sept., Cluj – Napoca, 2009

http://adems09.utcluj.ro/

D.Olaru, C.Stamate, G.Prisacaru,G.Ianus, New Micro Tribometers for Sliding and Rolling Friction, Proc. of 3rd Vienna International Conference on Nano-Technology, March 18 - 20, pp. 495-499, 2009, ISBN 978-3-901657-32-0, Vienna, Austria

D. Olaru, C.Stamate, A. Dumitrascu, G.Prisacaru, Experimental Investigations of Rolling Friction in Mechatronics Microsystems,Proc. of 2nd Int. Conference ADEMS’09, 24-25 Sept., Cluj – Napoca, 2009

G. C. Puiu,V. Puiu, D. Olaru, Friction in Ball – Screw Systems, Proc. of 2nd Int. Conference ADEMS’09, 24-25 Sept., Cluj – Napoca, 2009.

International Conference on Diagnosis and Prediction in Mechanical Engineering Systems (DIPRE’09) , Galati www.om.ugal.ro/dipre09/index.html

D.N. Olaru, C. Stamate, A. Dumitrascu , G. Ianus, Friction in the Microtribosystems. Influence of the Condensed Water, Acceptată pentru publicare în The Annals of University “Dunărea de Jos“ of Galaţi , Fascicle VIII, Tribology, 2009 (XV), ISSN 1221-4590 , revistă indexată în baze de date internaţionale , www.om.ugal.ro/AnnalsFasc8Tribology/index.htm



CONFERENCES

201015th INTERNATIONAL CONFERENCE ON EHD LUBRICATION AND TRACTION www.varehd.usv.ro

D.N.Olaru, C.Stamate, A.Dumitrascu, ROLLING FRICTION TORQUE IN MICROSYSTEMS, Proc. of 15th INTERNATIONAL CONFERENCE

ON EHD LUBRICATION AND TRACTION, Suceava, May, 6-8, 2010



PUBLICATIONSISI Journals

1.Olaru, D. N., Stamate, C., Prisacaru, Gh.: Rolling Friction in a Microtribosystem. Tribology Letters 35, 205-210, (2009) Revistă ISI, Impact factor 1.345;

2. D.Olaru, C.Stamate, A. Dumitrascu, G.Prisacaru, New Micro Tribometer for Rolling Friction, Manuscript Number: TRIL1128/2009, Tribology Letters, Revistă ISI, Impact factor 1.345;(Revision )

B. International Journals1. Dodun, O., Olaru, D. (et al.), Experimental study regarding electrostatic spray coating of solid lubricant for gears , International Journal of Material Forming, Springer Paris, 2008, vol. 1, no. 1, pp. 1335-1338

2. D.N. Olaru, C. Stamate, A. Dumitrascu , G. Ianus, Friction in the Microtribosystems. Influence of the Condensed Water, The Annals of University “Dunărea de Jos“ of Galaţi , Fascicle VIII, Tribology, 2009 (XV), ISSN 1221-4590 , revistă indexată în bazede date internaţionale (http://www.csa.com/ids70/serials_source_list.php?db=mechtrans-set-c )

C. Proposal of inventions

1. INERTIAL MICROTRIBOMETER 3BALLS, authors : D.Olaru, C.Stamate, G.Ianus, Gh. Prisacaru

2. MICROTRIBOMETER PIN ON DISC, authors: D.Olaru, C.Stamate, Gh. Prisacaru, G.Ianus

http://www.csa.com/ids70/serials_source_list.php?db=mechtrans-set-c



MOST IMPORTANT RESULTS1. Dimensional limits for capillary effects and adhesion

0

2

4

6

8

10

12

14

0 1 2 3 4 5 6 7 8 9 10

Ball diameter, mm

Fric

tion

para

met

er b

Dry conditions

Capillary effects

⎟⎠

⎞⎜⎝

⎛⋅

⋅⋅⋅= 428

15rM

Rb r

ρπ

⎟⎠

⎞⎜⎝

⎛⋅

⋅⋅= 4

1rM

RA r

r ρμ

A = (8.5 –9.4)10-4 s2.



0 0.5 1 1.5 2 2.5 30

0.002

0.004

0.006

0.008

0.01

150 rpm100 rpm60 rpm30 rpm

Time ( s )

Fric

tion

coef

ficie

nt

Dry contact, microballs with 1,588mm diameter Condensed water on surfaces, microballs with 1,588mm diameter



(Balls diameter 2 mm) (Balls diameter 4,762 mm)



2. Micro load limits for capillary effects in sliding friction

0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

0,4

1 11 21 31 41 51 61 71 81 91 101Time, s

Fric

tion

coef

ficie

nt

Dry conditions

Humidity conditions

00,050,1

0,150,2

0,250,3

0,350,4

1 11 21 31 41 51 61 71 81 91 101

Time, s

Fric

tion

coef

ficie

ntDry conditions

Humidity conditions

Normal load G=10mN Normal load G = 30 mN



3. Experimental investigations of the water meniscus developed in micro contacts

⎟⎟⎠

⎞⎜⎜⎝

⎛+⋅=⋅=

21

2 11RR

γxπApF cc Δ



4. New microtribometers4.1 New microtribometer pin on disc with normal load between (5-50) mN

rQμMdtωdJ rf ⋅⋅⋅=Σ=⋅ 32

dtωd

rgRμr

22

2⋅

⋅⋅=

Maximum contact pressure between balls and disc 2 is about 190MPa

R = 14.25mm,G = 28.05 mNQ = 9.42mN. r = 8.4 mm. ball diameters 1.588 mm.

22

22

dtφd

dtωd

=



4.2. Inertial microtribometer for rolling friction



tωtφ ⋅= 11 )(2)ln()ln(

2 )( tctbaetφ ⋅+⋅+=

5. New methodology to evaluate the friction coefficient in micro rolling contacts



22

2)cos(dtφd

rGαJμ ⋅

⋅⋅

=

The variation of the angular positions of the disc 2 for microballs having 1.588 mm and for angular speed of the disc 1 of: 40, 60, 90and 120 rpm

Variation of the friction coefficient between the balls and the disc 2, rotational speed of the disc 1:

40,60, 90 and 120 rpm



Validation of the methodology:

a) Comparison with experimental results obtained in [4][4] McCarthy, M., Waits, C. M., Ghodssi, R.: Dynamic Friction and Wear in a Planar-Contact Encapsulated Microball Bearing Using an Integrated Microturbine. Journal of Microelectromechanical Systems 18, 263-273 (2009)

Experimental values of friction coefficient obtained in [4] are between 0.0005(for 250 rpm and axial load of 50 mN) şi 0.025 (for 5000 rpm and axial load of10 mN).

The variation of the friction coefficient between the balls having 1.588 – mm diameter and the two discs using the spin - down method, for the rotational speed

of 40, 60, 90 and 120 rpm

b) Using SPIN-DOWN methodology )1()(2tBeAtφ ⋅−−⋅=

0 5 10 15 200

1 .10 4

2 .10 4

3 .10 4

4 .10 4

5 .10 4

40 rpm60 rpm90 rpm120 rpm

Time ( s )

Fric

tion

coef

ficie

nt

.

The variation of the angular position for the disc 2 when the disc 1 is stopped from the rotational

speed of 40, 60, 90 and 120 rpm, the microballshaving 1.588- mm diameter.





6. Elaboration of a new analytical model to determine the friction coefficient in a micro bearing

dtωdB

dtωdAμ b+= 2

1 )3(cos

gmGrαJAb ⋅⋅+⋅

⋅= )3(

cos3gmGαrmB

b

b⋅⋅+

⋅⋅⋅=

Friction coefficient in the contact of the disc 1 with the microball

Friction coefficient in the contact of the disc 2 with the microball

22

2

2cos

dtφd

rGαJμ ⋅

⋅⋅

=



THE ACTIVITY OF THE DOCTORAL STUDENTS IN THE PROJECT

1. Stamate Ciprian

Title of the Ph.D.Thesis THEORETICAL AND EXPERIMENTAL STUDY OF THE FRICTION IN MECHATRONICS AND BIOLOGICAL MICROSYSTEMS

1. STUDY OF THE RESEARCH REGARDING FRICTION IN MECHATRONICS AND BIOLOGICAL MICROSYSTEMS2. ROLLING FRICTION IN MICROSYSTEMS3. NEW METHODS AND EQUIPMENTS IN THE STUDY OF THE FRICTION IN MICROSYSTEMS4. WATER INFLUENCE ON THE FRICTION IN MICROSYSTEMS5. FORCES IN BIOLOGICAL MICROSYSTEMS6. CONCLUSIONS AND CONTRIBUTIONS

2. Puiu George Constantin

Title of the Ph.D.Thesis THEORETICAL AND EXPERIMENTAL STUDY OF THE FRICTION IN THE BALL SCREW SYSTEMS

1. STUDY OF THE RESEARCHES REGARDING THE FRICTION IN BALL SCREW SYSTEMS

2. NEW ANALYTICAL MODELS FOR FRICTION IN THE BALL SCREW SYSTEMS

3. NEW EQUIPMENTS AND METHODS FOR STUDY OF THE FRICTION IN BALL SCREW SYSTEMS

4. EXPERIMENTAL VALIDATIONS OF THE MODEL

5. CONCLUSIONS. CONTRIBUTIONS

researches for the decrease of the frictions in mechatronic

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