1. JAXA Activities on Micro-Nano Technology
Norimitsu KAMIMORI, Fumio IMAI,
Junichiro ISHIZAWA， Kazuyuki　MORI
Institute of Space Technology and Aeronautics (ISTA),
Japan Aerospace Exploration Agency (JAXA)
１）      序（はじめに）
今日は、宇宙環境利用の展望という課題で報告する機会を与えて下さいまして、有り難うございます。４０分戴いて、私の考えを述べさせていただきます。
最初に１～２分自分のことを申し上げますことをお許し下さい。私自身は長年、化学の分野、中でも有機導体、半導体で仕事をして参りました。東大理学部化学科、東大物性研、新設の岡崎の分子科学研究所にそれぞれ３分の１づつおり、４年前に宇宙環境利用の分野に参加しました。目下、懸命に勉強しつつ仕事に従事しております。
そして、現在までに学び得たことを通して宇宙環境利用の現況と将来について、私の考え方を述べてみたいと思います。

2. Practical Examples in JAXA
Contents
Introduction
Practical Examples in JAXA
(1) MW – CNT/Polyimide Composites
(2) Carbon Nanofiber (CNF)
(3) 3-D photonic crystal growth in micro-g
(4) Smart material for micro-machine
(5) Electrochemical Super Capacitor
Summary

3. Introduction In Japanese Science and Technologies,
Micro/Nano Technology is in major priorities
(IT, Life, Environment, and Nano-Technology).
In JAXA,
Micro/Nano Technology is in trial phase.
ISAS and ISTA researchers have taken efforts

4. Practical Examples in JAXA

5. (1) MW - CNT/Polyimide Composites
R&D Item: Triple A Polyimide (Tri-A PI) .
(Amorphous, Asymmetric, Addition type)
Tri-A PI is expected to be an innovative polymer
from its good fluidity and thermostability
(Tg>573K). 　
Potential Application:
Nose-Cone of reusable space launch vehicle
Cf. Ogasawara, T., Ishida, Y. and Yokota, R., “Characterization of multi-walled carbon nanotube/phenylethynyl terminated polyimide -composites,” Composites, Part A, 35 pp.67-74, 2004.

6. MW - CNT MW-CNT was chosen because of its availability and low cost.
(SW-CNT costs high for 　composite use.)
200 nm
MW-CNTs (FT-grade, CNRI Inc., Japan)
・Synthesized by CVD process.
・Diameters in the range of nm.
・Average lengths of mm.
・Highly entangled and randomly oriented.

7. Properties of the MW-CNT/Tri-A PI Composites
Test Result
Properties of the MW-CNT/Tri-A PI Composites
CNT
(wt%)
(vol%) Tg
(K) Ｅ
(GPa)
σuts
(MPa)
εmax
(%)
σ0.2
Sample-A
608
2.84
115.6
7.6
69.8
Sample-B
3.3
2.3
612
3.07
99.5
4.0
80.5
Sample-C
7.7
5.4
623
3.28
97.6
3.6
84.6
Sample-D
14.3
10.3
630
3.90
95.2
2.6
92.6

8. (2) Carbon Nanofiber (CNF)
Cup Stack Nanofiber (CSNF) by CVD Method
　　 produces by GSI Creos Corporation, JAPAN
CARBERE®
Schematic Illustration
Large Hollow Core, Relatively Longer Portion of Open Edges

9. Summary of Test Results
Strength of CFRP using CSNF resin(3 phases)
(Normalized by CFRP using non CSNF Resin Strengths)

10. (3) Oversized 3-D photonic crystal growth in micro-gravity
On the ground test, Convection and Strain disturb crystallization
Micro-g is best environment for Colloid crystallization
Colloid substance　
Nano particle (high refractive index)
Particle size: ca.100nm
Autonomy by means of electrostatic-repulsive force, etc.
Cf.
Optically Tunable Gelled Photonic Crystal Covering Almost the Entire Visible Light Wavelength Region.,
Y.Iwayama, J.Yamanaka, Y.Takiguchi, M. Takasaka, K.Ito, T. Shinohara, T. Sawada, and M. Yonese, Langmuir 19, 977 (2003)
Fabrication of Photonic Crystal Using Colloidal Particles., K.Ito,
Space material forum in Nagoya(2003)

11. Test Schedule Autumn, 2005 1st experiment in SM/ISS.
Summer～Autumn, 2006
2nd experiment in SM/ISS.
Now:
Preparing experiment (developing experimental apparatus)

12. (4) Smart material for micro-machine
Shape Memory Polymer (SMP) for space use.
→ High durability against space environments.
High reliability of shape recovery.
SMP has good processability.　→　Design flexibility
　　・molding
　　・cutting
　　・heat-sealing
SMP has possibility to miniaturize and simplify actuators.
Example )
Heat
SMP screws are manufactured by MHI

13. Concept of SMP micro-machine
Fix shape
Transform free
Mold into desired shape
Recover shape
Operate
High
Low
Glass Transition Temperature （Tg）
Temperature
Rubbery state
Glassy state
Flexible
Rigid
To maintain precise performance and stiffness, the Tg of SMPs should be above the temperature of the SMP structure in orbit.
Now, manufacturing trial models

14. SMPs Compared with Shape Memory Alloys
Shape Memory Polymers
Shape Memory Alloys
Recovery volume
400~500% 7%
Recovery power
Small
Large
Density
1 g/cm3
6.5 g/cm3
Workability
Good
(Thermoplastic)
Poor
Resistance to space environment
Low
High
Cost *
$50 /kg
$1000 /kg
*TRC report(1995)

15. Resistance of FR-SMP against UV,EB,AO
Changes in the storage modulus of FR-SMP
Small effects of irradiation. 　　(UV,EB,AO)
Irradiated samples curve closely match that of the unirradiated sample.
Irradiated samples satisfy the conditions of having good shape memory properties.
Change in storage modulus of FR-SMP 　　as a function of irradiation.

16. (5) Electrochemical Super Capacitor
JAXA is developing Double Layer Capacitor.
→　Long storage period.
→　High cycle of charge-discharge performance.
Focused on long storage period at low temperature.
Mounted on MINERVA.
(Robot lander carried by HAYABUSA,
lunched at )
Needs to increase surface area of electrode
for high electric capacity
high energy density
Nano technology like CNT/CNF may provide higher performance.
Now

17. JAXA’s plan at Double Layer Capacitor
2004 –
On-orbit demonstration
Power Supply
with high durability
Nano Material
Evaluate commercial technology
Nano material use at Electrode
Mounted on MINERVA.
-50F capacitor.
-Long storage period
-against high/low Temp.
Evaluate 5000F capacitor.
Nano materials provide higher electric capacity / higher energy density.

18. Summary In coming 2-3years: Trial phase and evaluation
Partnership with Private Company and Univ.
Promotion of International Cooperation
Increase actual budget in coming years