Research Article Volume 10 Issue 2
National Research University of Electronic Technology, MIET, Moscow, Russia
Correspondence: Afonin Sergey Mikhailovich, National Research University of Electronic Technology, MIET, 124498, Moscow, Russia, Tel 4997102233
Received: July 09, 2024 | Published: July 17, 2024
Citation: Afonin SM. A multi-layer electro elastic drive for micro and nano robotics. Int Rob Auto J. 2024;10(2):73-76. DOI: 10.15406/iratj.2024.10.00286
A multi-layer electro elastic drive of robotics is used in adaptive optics of compound telescope, scanning microscopy, interferometry and nanotechnology. For micro and nano robotics a multi-layer electro elastic drive is applied. The parametric model of a multi-layer electro elastic drive is determined. Its functions and matrix deformations are founded. The parameters of the multi-layer longitudinal PZT drive are determined.
Keywords: multi-layer electro elastic drive, multi-layer piezo drive, parametric model, micro and nano robotics.
A multi-layer electro elastic drive is used promising for micro and nano robotics in the micro and nano displacement.1−8 This drive based on the piezoelectric or electrostriction effects.9s−19 A multi-layer electro elastic drive of robotics is applied in adaptive optics of compound telescope, scanning microscopy, micro surgery, interferometry, nano pump, nano stabilization and nanotechnology.20−53 The deformations of a multi-layer drive are described with the matrix equation. Its parametric model, scheme and functions are obtained by using of mathematical physics method.
Parametric model
The parametric model6−53 of multi-layer piezo actuator with the voltage or current controlled are determined using the equation of inverse piezo effect in the form at the control of voltage
Si=dmiEm+sEijTjSi=dmiEm+sEijTj
at the control of current
Si=gmi Dm+sDijTjSi=gmiDm+sDijTj
here SiSi , EmEm , DmDm , TjTj , dmidmi , gmigmi , sEijsEij , sDijsDij are the relative deformation, the strength of electric field, the electric induction, the strength of mechanic field, the piezo module, the piezo constant, the elastic compliances at E=constE=const and at D=constD=const , and i, j, mi,j,m are the indexes.
The equation of the direct piezo effect has the form6−53
Dm=dmiTi+εTmkEkDm=dmiTi+εTmkEk
here εTmkεTmk is the dielectric constants at T=constT=const , k is the index
Then the electroelasticity equation of a multi-layer drive6−53 has the form
Si=vmiψm+sψijTjSi=vmiψm+sψijTj
here Ψ=E, DΨ=E,D is control parameter at the control of voltage and the control of current.
A multi-layer drive consist from the piezo layers connected the series mechanically and the parallel electrically [6 − 44]. We have the system of equations for T-form quadripole of k piezo layer
Fk inp(s)=−(Z1+Z2)Ξk(s)+Z2Ξk+1(s)Fkinp(s)=−(Z1+Z2)Ξk(s)+Z2Ξk+1(s)
−Fk out(s)=−Z2Ξk(s)+(Z1+Z2)Ξk+1(s)−Fkout(s)=−Z2Ξk(s)+(Z1+Z2)Ξk+1(s)
Z1=Soγth(δγ)sψij, Z2=Soγsψijsh(δγ)Z1=Soγth(δγ)sψij,Z2=Soγsψijsh(δγ)
where Z1Z1 , Z2Z2 , ss , δδ , γγ , Fk inp(s)Fkinp(s) , Fk out(s)Fkout(s) , Ξk(s)Ξk(s) , Ξk+1(s)Ξk+1(s) are the resistances of quadripole k piezo layer, the transform parameter, the thickness, the coefficient wave propagation, the Laplace transform of the forces at the input and output ends of k piezo layer, the transforms of the displacements at input and output ends of k piezo layer.
The system of the equations for k piezo layer has the form
−Fk inp(s)=(1+Z1Z2)Fkout(s)+Z1(2+Z1Z2)Ξk+1(s)−Fkinp(s)=(1+Z1Z2)Fkout(s)+Z1(2+Z1Z2)Ξk+1(s)
Ξk(s)=1Z1Fk out(s)+(1+Z1Z2)Ξk+1(s)Ξk(s)=1Z1Fkout(s)+(1+Z1Z2)Ξk+1(s)
This system is founded in the matrix form
[−Fk inp(s)Ξk(s)]=[M] [Fk out(s)Ξk+1(s)][−Fkinp(s)Ξk(s)]=[M][Fkout(s)Ξk+1(s)]
[M]=[m11m12m21m22]=[1+Z1Z2Z1(2+Z1Z1)1Z21+Z1Z2][M]=[m11m12m21m22]=⎡⎢⎣1+Z1Z2Z1(2+Z1Z1)1Z21+Z1Z2⎤⎥⎦
m11=m22=1+Z1Z2=ch(δγ), m11=m22=1+Z1Z2=ch(δγ), m12=Z1(2+Z1Z1)=Z0sh(δγ)m12=Z1(2+Z1Z1)=Z0sh(δγ)
m21=1Z2=sh(δγ)Z0, m21=1Z2=sh(δγ)Z0, Z0=S0γsψijZ0=S0γsψij
The equation of forces at the boundary between two layers is obtained in the form
Fk out(s)=−Fk+1 inp(s)Fkout(s)=−Fk+1inp(s)
For a multi-layer electro elastic drive with n layers and l length its system has the matrix form
[−F1 inp(s)Ξ1(s)]=[M]n [Fn out(s)Ξn+1(s)][−F1inp(s)Ξ1(s)]=[M]n[Fnout(s)Ξn+1(s)]
[M]n=[ch(nδγ)Z0sh(nδγ)sh(nδγ)Z0ch(nδγ)][M]n=[ch(nδγ)Z0sh(nδγ)sh(nδγ)Z0ch(nδγ)]
then
[M]n=[ch(lγ)Z0sh(lγ)sh(lγ)Z0ch(lγ)][M]n=[ch(lγ)Z0sh(lγ)sh(lγ)Z0ch(lγ)]
The equations of forces a multi-layer drive we have in the form
atx=0, Tj(0,s)S0=F1(s)+M1s2Ξ1(s)x=0,Tj(0,s)S0=F1(s)+M1s2Ξ1(s)
atx=l, Tj(l,s)S0=−F2(s)−M2s2Ξ2(s)x=l,Tj(l,s)S0=−F2(s)−M2s2Ξ2(s)
The transform of its force causes deformation has the equation in the form
F(s)=vmiS0ψm(s)sψijF(s)=vmiS0ψm(s)sψij
Then the parametric model and scheme on Figure 1 of a multi-layer electro elastic drive are obtained in the form
Ξ1 (s)=(1/(M1s2)){−F1(s)+(1/χψij)[vmiψm(s)−(γ/sh(lγ))××(ch(lγ)Ξ1(s)−Ξ2(s))]}Ξ1(s)=(1/(M1s2)){−F1(s)+(1/χψij)[vmiψm(s)−(γ/sh(lγ))××(ch(lγ)Ξ1(s)−Ξ2(s))]}
Ξ2 (s)=(1/(M2s2)){−F2(s)+(1/χψij)[vmiψm(s)−(γ/sh(lγ))××(ch(lγ)Ξ2(s)−Ξ1(s))]}Ξ2(s)=(1/(M2s2)){−F2(s)+(1/χψij)[vmiψm(s)−(γ/sh(lγ))××(ch(lγ)Ξ2(s)−Ξ1(s))]}
here vmi={d33, d31, d15 g33, g31, g15,vmi={d33,d31,d15g33,g31,g15, , Ψm={E3,E1D3,D1Ψm={E3,E1D3,D1 , sψij={sE33sE11sE55sD33sD11sD55sψij={sE33sE11sE55sD33sD11sD55 , cΨ={cEcDcΨ={cEcD , γ={γEγEγ={γEγE , χψij=sψij/S0χψij=sψij/S0 .
The matrix function of a multi-layer drive has the form
[Ξ1 (s)Ξ2 (s)]=[W11(s)W12(s)W13(s)W21(s)W22(s)W23(s)][ψm(s)F1(s)F2(s)][Ξ1(s)Ξ2(s)]=[W11(s)W12(s)W13(s)W21(s)W22(s)W23(s)]⎡⎢⎣ψm(s)F1(s)F2(s)⎤⎥⎦
then
[Ξ(s)]=[W(s)] [P(s)][Ξ(s)]=[W(s)][P(s)]
[Ξ(s)]=[Ξ1(s)Ξ2(s)][Ξ(s)]=[Ξ1(s)Ξ2(s)] ,[P(s)]=[Ψm(s)F1(s)F2(s)][P(s)]=⎡⎢⎣Ψm(s)F1(s)F2(s)⎤⎥⎦
[W(s)]=[W11(s)W12(s)W13(s)W21(s)W22(s)W23(s)][W(s)]=[W11(s)W12(s)W13(s)W21(s)W22(s)W23(s)]
The functions of a multi-layer drive are determined
W11(s)=Ξ1 (s)/ψm(s)=vmi[M2χψijs2+γth(lγ/2)]/AijW11(s)=Ξ1(s)/ψm(s)=vmi[M2χψijs2+γth(lγ/2)]/Aij
χψij=sψij/S0χψij=sψij/S0
Aij=M1M2(χψij)2s4+{(M1+M2)(χψij)/[cψth(lγ)]}s3++[(M1+M2)χψijα/th(lγ)+1/(cψ)2]s2+2αs/cψ+α2Aij=M1M2(χψij)2s4+{(M1+M2)(χψij)/[cψth(lγ)]}s3++[(M1+M2)χψijα/th(lγ)+1/(cψ)2]s2+2αs/cψ+α2
W21(s)=Ξ2 (s)/ψm(s)=−vψijM1χψijs2+γth(lγ/2)/Aij
W12(s)=Ξ1 (s)/F1(s)=−χψij[M2χψijs2+γth(lγ)]/Aij
W13(s)=Ξ1 (s)/F2(s)==W22(s)=Ξ2 (s)/F1(s)=[χψijγ/sh(lγ)]/Aij
W23(s)=Ξ2 (s)/F2(s)=−χψij[M1χψijs2+γ/th(lγ)]/Aij
The function of the multi-layer longitudinal piezo drive with one fixed face is determined at the elastic-inertial load and the control of voltage in the form
W(s)=Ξ2(s)U(s)=d33n(1+Ce/CE33) (T2ts2+2Ttξts+1)
Tt=√M2/(Ce+CE33) , ξt=αl2CE33/[3cE√M2(Ce+CE33)]
Its transient response has the form
ξ(t)=ξm(1−e−ξttTt√1−ξ2tsin(ωtt+ϕt))
ξm=d33nUm1+Ce/CE33 , ωt=√1−ξ2t/Tt , ϕt=arctg(√1−ξ2t/ξt)
For the multi-layer longitudinal PZT drive at Um =60 V, d33 = 4∙10-10 m/V, n= 8, M= 1 kg, CE33 = 5.8∙107 N/m, Ce = 0.6∙107 N/m its parameters ξm = 174 nm and Tt = 1.25∙10-4 s are obtained with error 10%.
We have the parametric model and scheme of a multi-layer electro elastic drive of robotics by using of mathematical physics method. The system of equations for T-form quadripole of piezo layer is used. For a multi-layer electro elastic drive its system has the matrix form. By using the equations of forces on ends of a multi-layer drive and the equation of force causes deformation its parametric model and scheme, functions are determined.
A multi-layer electro elastic drive of robotics is used in adaptive optics, scanning microscopy, micro surgery, interferometry, nanotechnology, nano pump, nano stabilization, compensation of deformations. The parameters of the multi-layer longitudinal PZT drive at the control of voltage are obtained.
The characteristics in of the multi-layer piezo drive are obtained by applied of mathematical physics method. Future works are planned to explore the multi-layer piezo drive for adaptive optics of compound telescope.
None.
Author declares that there is no conflict of interest.
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