The new gripper designs have been processed, showing 100% yield
Microgripper on COMSOL – vertical arm deflection
In order to support undergraduate projects, a number of COMSOL Multiphysics simulations have been created to determine the accuracy of experimental results. The two main projects this year centre around the thickness of the top SU8 layer and the impact of it on the moving speed of the device, and on the manual deflection of the arms and the associated stresses within the arm. Here’s a quick animation created in COMSOL showing an arm being deflected (please click on the image for the animation to start).
This simulation was created by applying a deflection in the z direction to the end of the gripper arm, which may result in the arm being stretched, therefore a more realistic approach was sought, in the form of an applied load to the end of the arm:
As can be seen, the difference appears to be minimal, however, the y component of the displacement is indeed fixed for a set z deflection. By comparison, when applying a mass, the y deflection varies by 11 microns.
More information on the other project to follow!
Thesis published online
My PhD thesis has now been published online, and can be found here.
C.K.A. Hill, L.E. Dodd, M.C. Rosamond and D. Wood, “Zero Temperature Coefficient of Resistivity in Nichrome” Proc. MicroMechanics Europe (MME 2013), Espoo, Finland, 1-4 September 2013, paper 17.
L.E. Dodd, A.J. Gallant and D. Wood, “Controlled reactive ion etching and plasma regrowth of titanium oxides of known thickness for production of metal-oxide- metal (MOM) diodes” IET Micro and Nano Letters, vol. 8, pp. 476 478, August 2013, DOI:10.1049/mnl.2013.0177.
L.E. Dodd, A.J. Gallant and D. Wood, “Failure Mechanisms in Metal-Oxide-Metal (MOM) Diodes“, Electronic Materials Conference (EMC), South Bend, USA 26-28 June, 2013, p 61 (oral presentation)
L.E. Dodd, A.J. Gallant and D. Wood, “Production of Metal-Oxide-Metal (MOM) Diodes Using Phase Shift Lithography“, Electronic Materials Conference (EMC), South Bend, USA, 26-28 June, 2013, p 61 (oral presentation)
Microgripper RA
As of 1st December 2013, Linzi will be working on the Durham Microgripper Project. The research explores the design, modelling, fabrication and testing of a thermoelectrically actuated microgripper for the manipulation of single cells and other biological particles. A suitable combination of conductive and polymeric materials together with the design of a highly efficient electro-thermal actuator has produced a microgripper that can be operated in air in in liquid environments without inducing electrolysis. It produces large deflections at low voltage and power. Micromanipulation experiments have successfully demonstrated the gripping, holding and positioning of a micro sized object.
D, Wood, J.M. Chamberlain, A.J. Gallant, A.J. Baragwanath, L.E. Dodd and C.K.A. Hill, “Micromachined Devices for Use in Terahertz Applications” Advances in Science and Technology, vol. 81, pp. 20-27, September 2012. DOI: 10.4028/www.scientific.net/AST.81.20
L.E. Dodd, A.J. Gallant and D. Wood, “Production of sub-micron metal-oxide-metal diodes using two novel techniques“, International Conference on Smart Materials, Structures and Systems, Montecatini Terme, Italy 2012, paper E:HP11 (poster presentation)
Dr Linzi E. Amers-Dodd 