觸覺迴授裝置之比較

目前市面上並無將 Electrotactile(電觸感)裝置應用於 I/F 裝置之用途，倒 是經電醫療復健輔助器材有部份產品已經問世。例如利用經電刺激肌肉神 經以達到減肥塑身的效果(ABTronic) 或是低周波經電按摩器(National EW-435P)

Tactile Feedback Actuator Technologies 觸感模擬驅動方式比較表

Technology Description Advantages Disadvantages

Piezoelectric crystals

Changing electric fields causes expansion and contraction of crystals

- High spatial resolution

- Restricted to resonant frequency

Pneumatic Takes many forms. As air-jets, provides an array of air nozzles that can be gated to a display pattern. As air-rings (cuffs), like miniature blood pressure cuffs. As bladders (bellows), often the size of a finger pad and held against the finger by a glove or band. As an array of tiny pressurized bladders, many to a single finger pad.

- Low mass on hand - Poor spatial and temporal resolution

- Limited bandwidth

Shape Memory Alloy

SMA wires and springs contract when heated and expand again as they cool under stress

- Good power-to-mass ratio

- Low efficiency during contraction

- Heat dissipation problems limit relaxation rate of wires

Solenoid Magnetic coil applies force to ferrous plunger

- High steady-state forces

- Better bandwidth than other materials (except for

piezoelectric crystals and

voice coils)

- Relatively heavy - Nonlinear, can require extra effort to control

Voice coil Voice coil vibrates to transmit low amplitude, high frequency vibrations to the skin.

- High temporal resolution - Relatively small, does not obstruct normal movement ranges of the fingers

- Poor spatial resolution - Limited scalability

Heat pump Solid state device that moves thermal energy to heat or cool the skin

- No fluids required - Poor spatial and temporal resolution - Bulky

- Limited bandwidth Electrode Solid state device that stimulates

coetaneous mechanoreceptors

- Low power consumption - Varies stimulus adjustment and quick off ideal.

- risk of heat burns - risk of shock

表 3 觸覺模擬驅動方式比較

從互動式 I/F 裝置而言，目前市場上主要運用為 Mechanical Force Feedback 裝置較為普遍，而 Vibration Tactile 相關之裝置則以 Immersion 公 司產品最為著名。目前市面上並無將 Electrotactile 裝置應用於 I/F 裝置之用 途(smart touch ) ，其相關技術比較表如下： (Ex.: WingMan RumblePad)

良 好

With Moving Mechanical parts

（具活動原件） Force Feedback (Ex.: iFeel Mouse)

良 好

With Moving Mechanical parts

（具活動原件） etic Vibrator）

10⁰

Electro-Tactile Force Feedback

不

美國麻省理工學院電子技術研究實驗室(RLE/MIT) Thomas E. von.

Wiegand 教授及約翰霍浦金斯大學(John Hopkins University) Allison

Okamura 教授均將觸感模擬之實施方式區分為 1.氣體 (Pneumatic) 2.微震 ( Vibrotactile) 3.電子(Electrotactile)4.靜態(Static) 等四大類。同時，Thomas E. von. Wiegand 教授更在其 2001 年 “Augmented Stimulation for Bodyworm Haptics” proposal [35 ]中直接指出電子式觸感模擬將會是未來一種較合宜 的發展方向。

四、電觸感迴授裝置

經皮神經電刺激（TENS, Transcutaneous Electrical Nerve

Stimulator/Stimulation）的發明，可回溯自古羅馬時，醫師用電鰻來治療人 的頭痛及關節炎。一直到數十年前發明機械後，人們才脫離以前的電魚療 法，使用較穩定的電流輸出，得到更有效的治療。而近幾年來由於研究及 科技的進展，使 EMS（Electronic Muscle Stimulation）的技術漸趨成熟並 且已經有多項相關的產品，如低週波治療器，肌肉訓練器等。

而 Electrical Tactile Display 的發展則是繼續上述技術的發展，在人類對於 神經元的訊號傳遞方式漸漸瞭解之後，嘗詴直接以電流傳遞的方式來取代 以往機械式的觸覺模擬方式。

目前對於電流觸發皮膚感覺受器的研究中，以美國 The University of Wisconsin 的 Tactile Communication & Neurorehabilitation Lab

http://tcnl.med.wisc.edu/home.php 以及日本 Tachi Lab http://tachilab.org/

等對於以電流刺激與觸感之相關研究較多。而經由上述機構相關之研究報