熱機的效率是熱力學中的核心議題，過去十年來膠體粒子動力學和技術的研究發展讓我們能夠在膠體系統中演示微米尺寸的熱機。然而，為何主動熱庫中的熱機能夠突破效率的極限，或是熱棘輪能否達到卡諾極限卻仍然充滿挑戰，因為創造可控制的位勢和溫度十分困難。在先前的研究中，我們成功的建立了用來解決以上難題的適當工具——回饋光阱，透過回饋的過程，在我們選擇的目標位置製造任意時空的位勢和隨機的雜訊（視為溫度）。在此我們提出回饋光阱中布朗熱機之系列實驗，以下為研究計畫概要。1. 我們將演示主動熱庫中的布朗熱機，搭配人造可控雜訊產生系統。已知主動熱庫中的效率超過卡諾效率，我們將找出何種特性的雜訊將影響效率並與實際細菌中的結果比較。2. 我們將實現效率仍具爭議並需要實驗印證是否能達到卡諾效率的Büttiker-Landauer 棘輪，並同時研究達到最大功率的最佳位勢 ;The efficiency of the heat engine is a central theme in thermodynamics. Advance in theories to describe dynamics and technologies to manipulate a colloidal particle allows us to demonstrate the micron-sized heat engine in the colloidal system over the past decade. However, why the efficiency in the active bath surpasses the maximal bound or whether the thermal ratchet can attain the Carnot limit are remained challenging due to the difficulty to produce controllable potential and temperature. In the previous study, we successfully developed the appropriate tool to answer these questions, called the optical feedback trap which can create arbitrary spatiotemporal potential and produce the random noises (considered as temperature) at the destination where we desire by the feedback process. Here, we propose the experiments of the Brownian heat engines that are possible only with the feedback trap. The following is an overview of the proposed research plan. (i) We will demonstrate the Brownian Carnot engine in the active heat bath with the well-controllable artificial noise-generating system. It is known that the efficiency in the active bath exceeds the Carnot efficiency. We will find out what characteristics of noises affect the efficiency of the engine and compare it to the results from the real bacterial bath. (ii) We will experimentally realize the Büttiker-Landauer ratchet whose efficiency is controversial and needed to be experimentally confirmed if the Carnot efficiency can be achievable. The optimal potential for maximum power will also be studied.
