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)

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

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

Practical Examples in JAXA

(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.

MW - CNT

MW-CNTs (FT-grade, CNRI Inc., Japan)・ Synthesized by CVD process.・ Diameters in the range of 20-100 nm.・ Average lengths of 1-100 mm.・ Highly entangled and randomly oriented.

200 nm

MW-CNT was chosen　　　　 because of its availability and low cost.

(SW-CNT costs high for 　composite use.)

Properties of the MW-CNT/Tri-A PI Composites

CNT(wt%)

CNT(vol%)

Tg(K)

Ｅ(GPa)

σuts

(MPa)

εmax

(%)

σ0.2

(MPa)

Sample-A 0 0 608 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

Test Result

(2) Carbon Nanofiber (CNF)

• Cup Stack Nanofiber (CSNF) by CVD Method

　　 produces by GSI Creos Corporation, JAPAN

Schematic Illustration

Large Hollow Core, Relatively Longer Portion of Open Edges

CARBERE®

Summary of Test Results

• Strength of CFRP using CSNF resin(3 phases)

(Normalized by CFRP using non CSNF Resin Strengths)CFRP strength

0.50

0.60

0.70

0.80

0.90

1.00

1.10

1.20

1.30

EP827 EP827/ AR10-5% EP827/ AR10-10% EP827/ AR50-5% EP827/ AR50-10%

TensionCompression

(3) Oversized 3-D photonic crystal growth in micro-gravity

Colloid substance　

Nano particle (high refractive index)Particle size: ca.100nmAutonomy 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)

On the ground test, Convection and Strain disturb crystallization Micro-g is best environment for Colloid crystallization

Test Schedule

Autumn, 2005　 1st experiment in SM/ISS.

Summer～ Autumn, 2006 2nd experiment in SM/ISS.

Now: Preparing experiment (developing experimental apparatus)

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.

(4) Smart material for micro-machine

HeatSMP screws are manufactured by MHI

Example )

To maintain precise performance and stiffness, the Tg of SMPs should be above the

temperature of the SMP structure in orbit.

Fix shape

Transform free

Mold into desired shape

Recover shape

Operate

High

Low

Glass Transition Temperature （ Tg ）

Tem

peratu

re

Low

Rubbery state

Glassy state

Flexible

Rigid

Concept of SMP micro-machine

Now, manufacturing trial models

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

WorkabilityGood(Thermoplastic) Poor

Resistance to space environment Low High

Cost * $50 /kg $1000 /kg

*TRC report(1995)

Resistance of FR-SMP against UV,EB,AO

Change in storage modulus of FR-SMP 　　as a function of irradiation.

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.

1.0E+07

1.0E+08

1.0E+09

1.0E+10

200 250 300 350 400 450 500

Temperature (K)

G'

(Pa)

Unirradiated

EB irradiated

UV irradiated

AO irradiated

Changes in the storage modulus of FR-SMP

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 2004.5)

Needs to increase surface area of electrodefor high electric capacity

high energy density Nano technology like CNT/CNF may provide higher performance.

(5) Electrochemical Super Capacitor

Now

2004 –

On-orbit demonstration

Mounted on MINERVA. -50F capacitor. -Long storage period -against high/low Temp.

Evaluate commercial technology

Power Supply

with high durability

Nano material use at Electrode

Evaluate 5000F capacitor.Nano materials provide higher electric capacity / higher energy density.

JAXA’s plan at Double Layer Capacitor

Nano Material

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