Micro- and Nanorobotics, and Self-Assembly

Scope and activities Microassembly, nanomanipulation, mobile robotics and their applications. The research is highly interdisciplinary, merging micro- and nano physics, self-assembly, robotics and automation. With micro- and nanorobotics and self-assembly as the key competence, the research group is actively working on many important research topics, e.g. self-assembly and hybrid microassembly and their applications in electronics and optoelectronics manufacturing, in-situ nanorobotic testing inside environmental scanning electronic microscope (ESEM), novel mobile microrobots, micromechatronic instruments for in vivo applications, and automation of micro- and nanorobotic systems.

Research highlights Novel micro- and nanorobotic tools and methods. i) Piezohydraulic micromanipulator, ii) Environment

controlled microassembly, iii) Automatic single paper fiber tests with microrobot and microfluidics, iv) 6 DOF fully automated microgripping and -manipulation, v) In vivo diagnosis capsule for bowel diseases, vi) Voice coil based hopping microrobot, vii) Nanomanipulation in ESEM.

Novel self-assembly techniques. i) Adhesive self-assembly on planar oleophilic/phobic patterns, ii) Water mist self-assembly, iii) Hybrid assembly using water droplet, iv) Self-assembly on patterns with various features, e.g. jagged edges, segmented patterns, and black silicon patterns.

Fundamentals of solid-liquid interactions. i) Numerical modeling of wetting and self-alignment, ii) Self-assembly in environmental scanning electron microscope (ESEM), iii) Physics of wetting on patterns of different topological structures and surface properties.

Self-alignment on segmented patterns. Self-alignment of a 730 × 730μm RFID

chip on a segmented pattern with 405μm gap, the initial bias is 40μm in both x

and y axis. The outline of the pattern is highlighted with red lines. Upper image:

side view; lower image: top view.

Self-alignment on patterns with jagged edges. (a) A 200µm x 200µm SU-

8 chip with edge jaggedness; (b) A SU-8 chip is placed on the top of

corresponding SU-8 chip with edge jaggedness; (c) the top chip is self-

aligned with the bottom chip.

(b) (a) (c)

Publications • Zhou, Q., Korhonen, P., Laitinen, J., Sjövall, S. “Automatic dextrous microhandling based on a

6 DOF microgripper”, Journal of Micromechatronics, Vol. 3, No. 3-4, pp. 359-387, 2006.

• Sariola, V., Zhou, Q. and Koivo, H.N. “Hybrid microhandling: a unified view of robotic handling

and self-assembly”, Journal of Micro-Nano Mechatronics, Vol. 4, No. 1-2, pp. 5-16, 2008.

• Sariola, V., Jääskeläinen, M., and Zhou, Q., “Hybrid microassembly combining robotics and

water droplet self-alignment”, IEEE Transaction on Robotics, Vol. 26, Issue 6, pp. 965 - 977,

2010.

• Chang, B., Sariola, V., Aura, S., Ras, R.H.A., Klonner, M., Lipsanen, H., and Zhou, Q.,

"Capillary-driven self-assembly of microchips on oleophilic/oleophobic patterned surface using

adhesive droplet in ambient air", Applied Physics Letters, vol 99, 034104, 2011.

• Chang, B., Routa, I., Sariola, V. and Zhou, Q., "Self-alignment of RFID dies on 4-pad patterns

with water droplet for sparse self-assembly", Journal of Micromechanics and

Microengineering, 21 095024, 2011.

• Chang, B., Sariola, V., Jääskeläinen, M., and Zhou, Q., "Self-alignment in the stacking of

microchips with mist-induced water droplets", Journal of Micromechanics and

Microengineering, vol. 21, 015016, 2011.

Oleophilic/phobic patterns for self-assembly. (a)

Gold patterns of 50 nm thickness on ormocer-polymer

substrate after functionalization with trichlorosilane; (b)

oil-drop-contact angle: 133° on oleophobic substrate;

(c) adhesive-drop-contact angle: 53° on oleophilic

pattern; (d) adhesive-drop-contact angle: 119° on

oleophobic substrate.

(b)

(a)

(d)(c)

Black silicon patterns. A SiO2

pattern on black silicon substrate

with fluoropolymer coating

Massively parallel assembly of microchips with size of 200µm x 200µm x 30µm. a)

Top chips are roughly placed on the top of the bottom chips with placement errors; b)

Water mist is delivered to the assembly site; c) Top chips are self-aligned with the

corresponding bottom chips and water evaporates.

(a) (b) (c)

Contact Information: Dr. Quan Zhou, Adj. Prof., Tel. +358 40 8550311, email: quan.zhou@aalto.fi P.O. Box 15500, 00076 Aalto, Finland

Hybrid handling technique. (a) Assembly site is on top of a micropart. (b) Droplet of

water is dispensed on the bottom part. (c) Microgripper approaches the release site with a

part. (d) Droplet contacts with the top part and wets between the parts, which forms a

meniscus. (e) Microgripper releases the part and the capillary force aligns the parts. (f)

Water between the two parts evaporates, which leaves the two parts aligned. (g) Image

sequence of the actual experiment, as viewed from the top side.

In vivo diagnostics capsule. A wireless capsule

developed for diagnosis of bowel diseases to help

doctors identify the nature of the symptoms. Data

gathered from microphone and accelerometer

have features that can distinguish the origin of

diseases. Clinical tests with pigs were carried out.

6 DOF microgripper. A piezoelectric 6 DOF

microgripper with two independent fingers in a

compact form. The position of each DOF can be

controlled. Automatic manipulation of objects in 6 DOF

has been demonstrated. The device has been used in

automatic inspection of optoelectronics.

Automatic single paper fiber testing. Automatic

apparatus for singulating paper fibers from liquid

mixture using microfluidics and machine vision,

followed by microgripping and force sensing to

test the strength of the fiber. Automatic robotic

tools are also used.