iMechanica - nanoindentation - Comments

Nanoindentation, Elastic properties, Substrate effect, Thin film

Li Han — Tue, 14 Oct 2008 15:33:39 -0400

Li Han

note

Huai Huang — Sun, 11 May 2008 08:21:26 -0400

changed some incorrect notes in ppt, maybe need more polish

please reprint

Flavio A. Bonilla — Mon, 03 Dec 2007 15:12:11 -0500

Dr. Oyen,

Please add me to the list: I don't have access to this journal either. Thank you!

Flavio Alejandro

Could I also ask for an

ColinGrant — Wed, 28 Nov 2007 11:56:17 -0500

Could I also ask for an emailed reprint of this paper ?

Regards

Colin

I need correction factors in JKR theory for elastic thin films

krishnaraokorada — Tue, 27 Nov 2007 02:27:40 -0500

Can you send me the details of correction in JKR theory for elastic thin films(200 to 300 microns)?

Viscoelastic nanoindentation in biological systems

Spiros Kassavetis — Mon, 12 Nov 2007 06:39:51 -0500

Very interesting topic!!! Unfortunately the institution that I work has not subscription to this journal. Is it possible to e-mail me (skasa@physics.auth.gr) a reprint of this paper? Thanks in advance.

Re: Viscoelastic nanoindentation in biological systems

Xiaodong Li — Mon, 29 Oct 2007 13:27:24 -0400

That is great! I think this review article is of interest to a lot of people. Can you please e-mail me the reprint. Thanks.

Residual stress/nanoindentation

Xiaodong Li — Sat, 13 Oct 2007 12:43:04 -0400

Can we extend nanoindentation applications to residual stress measurement? Very recently, Drs. T.E. Buchheit and R. Tandon published a paper in Journal of Materials Research. They found that compressive residual stress shifts the simulated load–displacement response toward increasing hardness, irrespective of tip geometry. This shift is shown to be primarily due to the direct influence of the residual stress for the “glass” case. Hardness changes and load–displacement curve shifts are explained by using the spherical cavity model. This is significant for in-depth understanding of residual stress/mechanical property relation and developing new functionality - residual stress measurement for new nanoindenters. Supporting experimental results on stressed glasses are provided. For more details, please see

T.E. Buchheit, R. Tandon, Measuring residual stress in glasses and ceramics using instrumented indentation, Journal of Materials Research, Vol. 22, No. 10, pp. 2875-2887

Bone specimen preparation and nanoindentation measurments

Gregory FAVARO — Tue, 25 Sep 2007 05:28:36 -0400

Dear all,

We are working a since 5 years in Bone and dentine application with Geneva Hospital
(Prof. Patrick Amman).
Actually in Geneva
they cut the bone with a microtome and polish its but the biggest difficulty is
to measure the Nanoindentation with the good hydratation! Actually we re-hydrated
the bones but we have develop a liquid cell to measure the bone in
humidity!

We really need to compare the result in wet atmosphere if we want simulate
the reality!

Please see this very interesting article about intrinsic Nanoindentation for
bones! http://www.csm-instruments.com/new/contenus/e/doc/bulletins/AB_24.pdf

Do not hesitate to contact me for furteher information

Bone specimen preparation

MichelleLOyen — Mon, 03 Sep 2007 05:55:36 -0400

A slow diamond saw (like Buehler Isomet) is also very common and quite useful for bone and tooth specimen preparation, and allows for samples with more variety in sizes than microtoming.

More discussion during MRS meeting

Rohit Khanna — Mon, 03 Sep 2007 01:36:48 -0400

Thank you Prof Michelle for the response. I did not get much responses from imehanica community. may be this subject is not of great interest to many of imechanica members. I hope by coming MRS meeting, i will have a good reason to tell you, why research in this direction is important. You are absolutely right in saying that hydration state limits adhesion. It may be good to study on fundamental science aspect.

I have a poster in your symposium on Fundamentals of nanoindentation and nanotribology. It will be great to have useful discussion with you. This time, i don't see a big crowd of researchers for this symposium.

Best wishes,

Rohit

Adhesion, nanoindentation and biological things

MichelleLOyen — Sat, 01 Sep 2007 14:03:04 -0400

Very nice summary, Rohit.

Just one comment on perhaps why this has been a bit neglected as a topic... many of the biological materials of interest to researchers are fundamentally hydrated. For example, tissues in the body are in wet environments, as are plant materials. The hydration state has a fundamental effect in these materials' mechanical behavior in general, but also seems to limit the adhesion with a hard, stiff indenter. In fact, I had a colleague once tell me to put a thin water film on PDMS and that would limit adhesion effects in AFM-based indentation analysis.

Educational workshops

Rohit Khanna — Fri, 31 Aug 2007 00:03:16 -0400

Hi, Ferguson... i read your opinion about the current state of the research about mechanics of soft materials. I agree with you that there are also non-experts also in this field which may be biologist, material scientists etc.... May be because of lack of exposure in this field, the research has not progressed much in this direction. It is practically impossible for just one or two groups to be active in this area, the contribution has to come from a large group of researchers and then, only we can expect advancement in science and technology. I personaly believe that experts in this field should take the initiative to educate the researchers who are non-experts in this field. It may be good to organize educational workshops. I had been to such a workshop, quite recently in UIUC, on Cell mechanosenstivity, which dealt with various topics of interest like cell adhesion, cell mechanics, cell-biomaterial interactions etc. Experts in the field like Prof. Dennis Discher (UPENN), Prof. Michael Sheetz and many others, presented a review of the literature in these topics, and we also had hands-on experience on some experiments.

I hope to know your opinion on this.

Best wishes,

Rohit Khanna

Adhesion effects in nanoindentation

Rohit Khanna — Thu, 30 Aug 2007 23:46:11 -0400

Apart from the review of biomechanics literature presented by Michelle, Li and others, there are another important issues which need to be addressed. I agree that bonding is quite different in soft materials. Another research field which is not majorly touched by many of the researchers is the adhesion effects seen during unloading from a soft substrate. They do affect the elastic modulus measurement. There have been recent studies on such effects on soft material like polydimethysiloxane (PDMS). We know that there are limitations on the part of instrumentation unavailability, due to which accurate determination of time-dependent properties of soft materials has not been succeded to much extent. But i am surprised, why research has not progressed in looking at adhesion effects in nanoindentation. There has been model development to take into account such effects for last 35 years. First paper had come from Prof. K L Johnson who did a pioneered in establishing the theory of adhesion effects.

One can not ignore adhesion effects without which accurate determination of elastic modulus is not possible as far as my understanding is concerned.

I have done some review on this topic with the hope that it does not go un-noticed.

Adhesion is observed as a region of negative load during unloading in a load-displacement curve. Adhesion between the diamond tip and the sample can interfere with the measurement of indentation modulus using the compliance method for polymers and tissues [1-4]. Recent research reports on nanoindentation of soft polymers [1,4] have mentioned that the compliance method overestimates the modulus when there is significant tip-sample adhesion. For indentation with spherical tip, Johnson-Kendall-Roberts (JKR) [5] adhesion model has been shown to be give more accurate measurement of sample modulus [1,4,6]. The JKR method can be described as, first starting the indent out of contact and then capturing a full force curve as the tip approaches, indents, and retracts from the sample [6-8]. These force curves have been commonly used in AFM to measure the adhesive forces [9,10], but not yet applied to many nanoindentation studies of biomaterials.

1. Carrillo, F., et al., J. Mater. Res.(2005) 20, 2820
2. Klapperich, C., et al., J. Tribol. – Trans. ASME(2001) 123, 624.
3. Grunlan, J. C., et al., Rev. Sci. Instrum.(2001) 72, 2804
4. Carrillo, F., et al., J. Mater. Res.(2006) 21, 535
5. Johnson, K. L., et al., Proc. R. Soc. London, Ser. A(1971) 324, 301.
6. Ebenstein, D. M., and Wahl, K. J., J. Colloid Interface Sci.(2006) 298, 652
7. Wahl, K. J., et al., J. Colloid Interface Sci.(2005) 296, 178
8. Giri, M., et al., Langmuir (2001) 17, 2973.
9. Butt, H. J., et al., Surf. Sci. Rep.(2005) 59, 1
10. Cappella, B., and Dietler, G., Surf. Sci. Rep.(1999) 34, 1

----------------------------

Best regards,

Rohit Khanna

Hello Professor Thank you

Chul jin Syn — Thu, 30 Aug 2007 10:45:35 -0400

Hello Professor

Thank you for your suggestion.

We used the water jet to prepare bone specimens. The microtome method will be worked for ideal specimens.