This paper presents the inkjet-printed flexible temperature and humidity sensor(F-TH sensor) using PEDOT:PSS. The series, meshand parallel type sensing element using PEDOT:PSS ink was printed on the overhead projector(OHP) film. The fabricated sensor ofeach structure has the temperature sensitivity of 140 Ω/ o C, 29 Ω/ o C and 1.4 Ω/ o C with linearity, respectively. Also the fabricated sensorwas not only possible to measure a temperature, but also to detect humidity. The humidity sensitivity of 400 Ω/%RH, 3.4 Ω/%RH and3 Ω/%RH with linearity, respectively. The fabricated F-TH sensor is expected for the various applications such as electronic devices,bio-healthcare, industrial field.Keywords: Inkjet print, Flexible sensor, Temperature sensing, Humidity sensing 1. 서론 최근 유연한 전자기기에 대한 관심이 높아지고 있으며, 이애 따라 유연성 기판의 사용이 용이한 인쇄 전자 산업 및 인쇄 전자 기술에 대한 관심도 함께 높아지고 있다[1-6]. 잉크젯 프린팅은 비접촉식 프린팅 기술로써 노즐로부터 액적(drop)을 분사하여 기판위에 패턴을 직접 인쇄하는 기술이다. 기존의 포토리소그래피 기술과 비교하였을 때 빠른 패턴 제작이 가능하고, 공정과정이 줄어시간과 공정비용을 절감할 수 있으며, 재료의 낭비가 적어 전자기기, 의료·바이오, 산업 분야 등에서 유용한 기술이다. 현재 잉크젯 프린팅 공정을 이용하여 인쇄 전자 소자 제작 및 유연성 회로,디스플레이, 센서, 배터리 등의 인쇄 전자 기기에 적용하기 위한연구가 많이 진행되고 있다[7,8]. 잉크젯 프린팅 기술은 대부분 전도성 잉크를 이용하여 프린트회로기판(PCB), RFID, 전극 및 배선등의 소자분야에 적용[9-12]뿐만 아니라, LCD 칼라필터 공정 등에 적용되고 있다[13]. 이러한 잉크젯 프린팅 기술로 제작하는 센서의 경우 가볍고, 공정이 간단하며, 저렴한 공정비용, 유연성 기판 적용이 가능하고, 상온 공정 등의 장점이 있어 유연성 전자기기의 구동 소자로서 각광받고 있다. 잉크젯 프린팅 기술을 이용한유연성 센서의 개발은 경량화, 간편화, 휴대성 등의 강점을 가지고 있어서 유비쿼터스 시대에 활용하기 위한 유용한 소자이다. 본 연구에서는 유연한 기판 위에 유기태양전지에 주로 사용되는 P형 전도성 고분자 물질인 PEDOT:PSS 잉크를 이용하여,잉크젯 프린팅 기법으로 유연성 온·습도 감지 소자를 개발하고, 구조 별 소자의 특성을 비교했다.

http://koreascience.or.kr:80/article/JAKO201512053817013.pdf

Fabrication of Flexible Temperature & Humidity Sensor Using Inkjet-printing Technology

Targeting the cell nucleus remains a challenge for drug delivery. Here we present a universal platform for smart design of nano-particles (NPs) decoration that allows recruitment of multiple dynein motors to drive their active motion towards the nucleus. The uniqueness of our approach is based on using: (i) a spacer polymer, commonly Biotin-Polyethylene-glycol-thiol (B-PEG-SH), whose grafting density and molecular weight can be tuned thereby allowing NP transport optimization, and (ii) protein binding peptides, like cell penetrating, NLS, or cancer targeting, peptides. Universal chemistry is employed to link peptides to the PEG free-end. To manifest our platform, we use a SV40T large antigen-originating NLS peptide. Our modular design allows tuning the number of recruited motors, and to replace the NLS by a variety of other localization signal molecules. Our control of the NP decoration scheme, and the modularity of our platform, carries great advantage for nano-carrier design for drug delivery applications.

Smart-design of universally decorated nano-particles for drug delivery applications driven by active transport

Native cargos achieve efficient intra-cellular active transport by recruiting multiple motors proteins from the cytoplasm. Here we investigate the motion of spherical nano-particles (NPs), acting as model cargos, grafted with flexible polymers, each ending with a nuclear localization signal (NLS) peptide, thereby allowing recruitment of mammalian cytoplasmic dynein. Bead-motility assays show several unique features. As the number of motors increases, the run-time and run-length increase, the longitudinal velocity mean decreases, whereas its width shows a non-monotonous behavior. Moreover, both single and multi-motor NPs perform angular (i.e., projected transverse) motion. Strikingly, the directions of angular and longitudinal motions are correlated, such that retrograde steps are combined with right-handed motion. We formulate a theoretical model to simulate the multi-dynein transported NP. The model builds on a recently theoretical description of single yeast dynein stepping on the curved microtubule surface, modified to account for mammalian dynein, and generalized to include motor-motor elastic and excluded-volume coupling. The simulation results are majorly in agreement with our experimental results. Moreover, long time trajectories exhibit both left- and right- handed helical motion around the MT symmetry axis, consistent with the measured and simulated angular velocity. The model gives further insight into the mechanism of the NP motion and suggests that the NPs are self-regulating the number of participating motors, optimizing between single motor, for obstacle bypassing, and multi-motor behavior, for persistent directional motion. We suggest that native cargos could use a similar mechanism to achieve efficient transport in the crowded cellular environment.

/pdf/nano-particles-carried-by-multiple-dynein-motors-a-self-24r72phzdo.pdf

Nano-particles carried by multiple dynein motors: A Self-Regulating Nano-Machine

Describes the design of a reusable microfluidic flow cell for real time DNA detection. This Microfluidic-Device-Stamp-System (MDSS) is realized by a microstructured Silicon-Polymer-Hybrid that is pressed onto a sensing element consists of thin metallic interdigitated electrodes with immobilized capture DNA for hybridization detection. The hybridization temperature is controlled by integrated heating and sensing elements manufactured with standard microsystem technologies. Two-dimensional FEM flow analyses using ANSYS 5.5/FLOTRAN were done to optimize the homogeneities of fluid flow and DNA mass transport in the sensing region.

W. Benecke

Papers

Flexible microfluidic-device-stamp-system with integrated electrical sensor for real time DNA detection