Bespoke Projects
NuNano started life manufacturing unique cantilever sensors for research projects at the University of Bristol. Consequently, we have experience in taking a project from the drawing board, through production, to completion.
It’s always fascinating to hear of new instrumentation and applications arising from the worldwide nanoscience community. At NuNano we understand that these often require unique sensors to power them and would be only too happy to help you further your knowledge and understanding of the nanoscale world.
Showcased below are three varied examples of bespoke projects NuNano has completed for customers.
Ultra-soft Tip-less Cantilevers for Vertical Orientation
T Shaped Torsional Tapping Cantilevers
Bespoke Silicon Beams
Ultra-soft Tip-less Cantilevers for Vertical Orientation
These ultra-soft probes were designed for non-conventional AFM systems, capable of detecting lateral or shear forces acting on the cantilever (e.g. Shear Force Microscopy, Transverse Dynamic Force Microscope). They operate in a vertical orientation which allows much more sensitive cantilevers to be used, since the cantilevers do not experience jump-to-contact events associated with using low-spring constant cantilevers for conventional AFM.
NuNano designed extremely soft tip-less probes with spring constants in the range 0.003 – 6000 pN/nm. Different designs included a variety of cantilever lengths on the same chip, as well as probes with arrays of 10 identical cantilevers. These probes were fabricated from super-low-stress (non-stoichiometric) silicon nitride films on a standard silicon chip, with thicknesses of 50, 100 and 200 nm, but this could be further tailored to meet our customer's requirements.
“We have been working with NuNano ever since they started making AFM probes commercially. They have built considerable expertise in microcantilever fabrication, which has enabled them to create some of the softest cantilevers ever made. These cantilevers have been crucial for our research and have allowed us to measure forces at least 1000 times smaller than conventional AFM allows. By combining these cantilevers with our instrumentation, we can now measure the movement of molecular motors, observe conformational changes of proteins, measure adhesion forces on protocells and detect extremely weak optical forces. None of this would be possible using conventional AFM probes.”
Publications
T. Scholz, J.A. Vicary, G.M. Jeppesen, A. Ulcinas, J.K.H. Hörber, M. Antognozzi (2011). “Processive behaviour of kinesin observed using micro-fabricated cantilevers”. Nanotechnology, 22, 095707. http://iopscience.iop.org/article/10.1088/0957-4484/22/9/095707/pdf
R.L. Harniman, D. Plana, G.H. Carter, K.A. Bradley, M.J. Miles & D.J. Fermin (2017). “Real-time tracking of metal nucleation via local perturbation of hydration layers”. Nature Communications 8, 971. http://www.nature.com/articles/s41467-017-01087-1
T Shaped Torsional Tapping Cantilevers
Researchers at The Biophysical Imaging Centre in the Department of Physics and Astronomy at The University of Sheffield contacted NuNano with a specialist requirement for Torsional AFM probes. In Torsional Tapping mode, torsional oscillation of the cantilever is required, not ‘flexural’ oscillation as with standard tapping mode AFM. This can lead to increased lever sensitivity, quality factor and resonant frequency, as well as improved spatial resolution when scanning soft materials.
Torsional AFM measurements require T-shaped cantilevers, with the tip displaced from the central cantilever axis, to allow torsional bending of the lever around the central axis during imaging. NuNano were able to design, manufacture and deliver T-shaped silicon cantilevers with silicon tips, ideal for use in torsional modes.
“The process of getting from an idea to a functioning probe was really straightforward - we got quick, reliable answers for tolerances, specs, process limitations, timescales and cost. ”
Bespoke Silicon Beams
Dr James Bowen from The School of Engineering & Innovation at The Open University required a large bespoke set of tipless silicon cantilevers. By attaching colloid beads to the levers, they can be used for friction and adhesion analysis on nanoscale polymer liquid films e.g., in hair products.
He specifically needed cantilevers significantly stiffer than those commercially available. Dr Bowen noted that “Commercial cantilevers finish their spring constants around 50 N/m but that’s where my cantilevers start from, up to 3,000 N/m, and even up to 10,000 N/m.”
NuNano fabricated 40 different cantilever designs with spring constants ranging from 15 N/m to 28,000 N/m. Dr Bowen now has a toolbox of different spring constant levers which can be chosen to suit different samples such as measuring micro/nano friction on architecturally difficult surfaces.
Read more about this project on our blog.
“We approached NuNano with a requirement for the design and manufacture of a bespoke collection of silicon beams. We were kept informed at every stage of the project, and were delighted with the beams when they finally arrived. Not only was the project great value-for-money, the beams have transformed our ability to perform micro- and nano-mechanical characterisation of complex materials. We are planning our next project currently. We cannot recommend NuNano highly enough!”
If you have other microfabrication requirements please do not hesitate to get in touch. If we can't help you ourselves, we can certainly forward your details onto people who can.