本研究分為兩部份，第一部份觀察純水液滴撞擊具不同疏水性(90o≤θ≤160o)之石墨(Graphite)板的氣泡捕捉行為；第二部份為純水液滴撞擊不同粗糙度(15≤Rq≤1159nm)之聚碳酯酸(Polycarbonate)板的氣泡捕捉行為。使用高速攝影機拍攝純水液滴撞擊平板後的側視圖連續影像，並在45o角拍攝液滴撞擊平板的俯視圖，來觀察撞擊後之氣泡捕捉行為。
純水-石墨系統中，藉由控制不同液滴大小(1.93≤D0≤4.90 mm)和改變不同液滴撞擊速度(0.11≤Vi≤0.74 m/s)，獲知當石墨平板越疏水，越易發生氣泡捕捉，被捕捉的氣泡在狀態穩定後，會形成一個近似於圓形的氣泡。純水-聚碳酯酸板系統中，藉控制不同液滴大小(2.13≤D0≤3.87 mm)和改變不同液滴撞擊速度(0.14≤Vi≤0.59 m/s)，獲知氣泡捕捉較易發生在粗糙度較大的聚碳酯酸板上。在固定液滴大小和基板粗糙度時，有兩段氣泡捕捉的速度區間；平板粗糙度越大，其氣泡捕捉越易呈兩段速度區間。藉由分析捕捉的氣泡大小，得知於粗糙度越大時其捕捉之氣泡越大。另外在純水-聚碳酯酸板系統中發現了三個不同於以往在純水-parafilm和純水-石墨系統中的氣泡捕捉機制。

The phenomenon of bubble entrapment was studied for water drop impinging on graphite and polycarbonate substrates in this work. Four graphite substrates with advancing contact angle (90, 120, 140 and 160o and eight PC substrates with roughness, 15<Rg <1159 nm, were used in this study. Two high speed CD cameras with 6770 fps were utilized for studying the relaxation of drop morphology: one for side view and the other for top view images.
In the water drop impinging on graphite experiment, droplet size (1.93≤D0≤4.90 mm) and impact velocity (0.11≤Vi≤0.74 m/s) were adjusted. Bubble entrapment occurred more frequently for a more hydrophobic graphite surface. At a fixed drop size, bubble entrapment takes place only in a limited range of impact velocity.
In the experiment of water drop impinging on PC substrate, drop size (2.13≤D0≤3.87 mm) and impact velocities (0.14≤Vi≤0.59 m/s) were also adjusted. Bubble entrapment took place more frequently on a rough PC substrate. At a fixed drop size, bubble entrapment was observed in one or two ranges of impact velocity. The two-range of bubble entrapment occurred more on the rough PC substrates. Beside, three new bubble formation mechanisms were observed in the water-PC substrate system.

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